CN111272841A - Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof - Google Patents
Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof Download PDFInfo
- Publication number
- CN111272841A CN111272841A CN202010108443.8A CN202010108443A CN111272841A CN 111272841 A CN111272841 A CN 111272841A CN 202010108443 A CN202010108443 A CN 202010108443A CN 111272841 A CN111272841 A CN 111272841A
- Authority
- CN
- China
- Prior art keywords
- cus
- doped graphene
- composite material
- nitrogen
- graphene composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004005 microsphere Substances 0.000 title claims abstract description 149
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 120
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 119
- 239000002131 composite material Substances 0.000 title claims abstract description 102
- 239000011258 core-shell material Substances 0.000 title claims abstract description 96
- 238000002360 preparation method Methods 0.000 title claims abstract description 25
- OUYCCCASQSFEME-UHFFFAOYSA-N tyrosine Natural products OC(=O)C(N)CC1=CC=C(O)C=C1 OUYCCCASQSFEME-UHFFFAOYSA-N 0.000 claims abstract description 89
- OUYCCCASQSFEME-QMMMGPOBSA-N L-tyrosine Chemical compound OC(=O)[C@@H](N)CC1=CC=C(O)C=C1 OUYCCCASQSFEME-QMMMGPOBSA-N 0.000 claims abstract description 88
- 238000001514 detection method Methods 0.000 claims abstract description 60
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims abstract description 48
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000006243 chemical reaction Methods 0.000 claims abstract description 23
- 238000003756 stirring Methods 0.000 claims abstract description 19
- 239000006185 dispersion Substances 0.000 claims abstract description 16
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 claims abstract description 16
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims abstract description 15
- PLKATZNSTYDYJW-UHFFFAOYSA-N azane silver Chemical compound N.[Ag] PLKATZNSTYDYJW-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000007788 liquid Substances 0.000 claims abstract description 15
- 239000008367 deionised water Substances 0.000 claims abstract description 12
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 12
- 238000005406 washing Methods 0.000 claims abstract description 11
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 8
- MPTQRFCYZCXJFQ-UHFFFAOYSA-L copper(II) chloride dihydrate Chemical compound O.O.[Cl-].[Cl-].[Cu+2] MPTQRFCYZCXJFQ-UHFFFAOYSA-L 0.000 claims abstract description 8
- 239000011259 mixed solution Substances 0.000 claims abstract description 8
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims abstract description 7
- 239000008103 glucose Substances 0.000 claims abstract description 7
- 235000013305 food Nutrition 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims description 35
- 230000003647 oxidation Effects 0.000 claims description 30
- 238000007254 oxidation reaction Methods 0.000 claims description 30
- 238000001903 differential pulse voltammetry Methods 0.000 claims description 25
- 239000000243 solution Substances 0.000 claims description 24
- 239000000523 sample Substances 0.000 claims description 23
- 229910021397 glassy carbon Inorganic materials 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 16
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 14
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 13
- 238000000835 electrochemical detection Methods 0.000 claims description 12
- 238000005259 measurement Methods 0.000 claims description 11
- 239000000047 product Substances 0.000 claims description 10
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(I) nitrate Inorganic materials [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 claims description 7
- 238000001027 hydrothermal synthesis Methods 0.000 claims description 7
- 229910052697 platinum Inorganic materials 0.000 claims description 7
- 239000012086 standard solution Substances 0.000 claims description 7
- 238000009210 therapy by ultrasound Methods 0.000 claims description 7
- 238000005303 weighing Methods 0.000 claims description 7
- 230000004048 modification Effects 0.000 claims description 6
- 238000012986 modification Methods 0.000 claims description 6
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 5
- 239000002244 precipitate Substances 0.000 claims description 5
- 239000012488 sample solution Substances 0.000 claims description 5
- 230000002194 synthesizing effect Effects 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 2
- OMZSGWSJDCOLKM-UHFFFAOYSA-N copper(II) sulfide Chemical compound [S-2].[Cu+2] OMZSGWSJDCOLKM-UHFFFAOYSA-N 0.000 description 40
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 24
- 230000004044 response Effects 0.000 description 11
- 239000000126 substance Substances 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 239000002114 nanocomposite Substances 0.000 description 6
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000002484 cyclic voltammetry Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 230000035945 sensitivity Effects 0.000 description 4
- QZAYGJVTTNCVMB-UHFFFAOYSA-N serotonin Chemical compound C1=C(O)C=C2C(CCN)=CNC2=C1 QZAYGJVTTNCVMB-UHFFFAOYSA-N 0.000 description 4
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 4
- QAIPRVGONGVQAS-DUXPYHPUSA-N trans-caffeic acid Chemical compound OC(=O)\C=C\C1=CC=C(O)C(O)=C1 QAIPRVGONGVQAS-DUXPYHPUSA-N 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 239000007853 buffer solution Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000000634 powder X-ray diffraction Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- ACEAELOMUCBPJP-UHFFFAOYSA-N (E)-3,4,5-trihydroxycinnamic acid Natural products OC(=O)C=CC1=CC(O)=C(O)C(O)=C1 ACEAELOMUCBPJP-UHFFFAOYSA-N 0.000 description 2
- PWKSKIMOESPYIA-UHFFFAOYSA-N 2-acetamido-3-sulfanylpropanoic acid Chemical compound CC(=O)NC(CS)C(O)=O PWKSKIMOESPYIA-UHFFFAOYSA-N 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 2
- XUJNEKJLAYXESH-REOHCLBHSA-N L-Cysteine Chemical compound SC[C@H](N)C(O)=O XUJNEKJLAYXESH-REOHCLBHSA-N 0.000 description 2
- QIVBCDIJIAJPQS-VIFPVBQESA-N L-tryptophane Chemical compound C1=CC=C2C(C[C@H](N)C(O)=O)=CNC2=C1 QIVBCDIJIAJPQS-VIFPVBQESA-N 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 description 2
- QIVBCDIJIAJPQS-UHFFFAOYSA-N Tryptophan Natural products C1=CC=C2C(CC(N)C(O)=O)=CNC2=C1 QIVBCDIJIAJPQS-UHFFFAOYSA-N 0.000 description 2
- NDAUXUAQIAJITI-UHFFFAOYSA-N albuterol Chemical compound CC(C)(C)NCC(O)C1=CC=C(O)C(CO)=C1 NDAUXUAQIAJITI-UHFFFAOYSA-N 0.000 description 2
- 229940024606 amino acid Drugs 0.000 description 2
- 150000001413 amino acids Chemical class 0.000 description 2
- 238000004082 amperometric method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229940074360 caffeic acid Drugs 0.000 description 2
- 235000004883 caffeic acid Nutrition 0.000 description 2
- 238000005251 capillar electrophoresis Methods 0.000 description 2
- QAIPRVGONGVQAS-UHFFFAOYSA-N cis-caffeic acid Natural products OC(=O)C=CC1=CC=C(O)C(O)=C1 QAIPRVGONGVQAS-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001318 differential pulse voltammogram Methods 0.000 description 2
- 238000001917 fluorescence detection Methods 0.000 description 2
- 238000004817 gas chromatography Methods 0.000 description 2
- 238000004128 high performance liquid chromatography Methods 0.000 description 2
- 229960002163 hydrogen peroxide Drugs 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 238000004255 ion exchange chromatography Methods 0.000 description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 2
- 238000001499 laser induced fluorescence spectroscopy Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 238000004949 mass spectrometry Methods 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 239000002135 nanosheet Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229960005489 paracetamol Drugs 0.000 description 2
- 238000001420 photoelectron spectroscopy Methods 0.000 description 2
- 238000002186 photoelectron spectrum Methods 0.000 description 2
- -1 polytetrafluoroethylene Polymers 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 238000000083 pulse voltammetry Methods 0.000 description 2
- 229960002052 salbutamol Drugs 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 description 2
- 235000010288 sodium nitrite Nutrition 0.000 description 2
- 229960000819 sodium nitrite Drugs 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 239000006228 supernatant Substances 0.000 description 2
- 229960000943 tartrazine Drugs 0.000 description 2
- UJMBCXLDXJUMFB-GLCFPVLVSA-K tartrazine Chemical compound [Na+].[Na+].[Na+].[O-]C(=O)C1=NN(C=2C=CC(=CC=2)S([O-])(=O)=O)C(=O)C1\N=N\C1=CC=C(S([O-])(=O)=O)C=C1 UJMBCXLDXJUMFB-GLCFPVLVSA-K 0.000 description 2
- 239000004149 tartrazine Substances 0.000 description 2
- 235000012756 tartrazine Nutrition 0.000 description 2
- 229960004799 tryptophan Drugs 0.000 description 2
- 238000000825 ultraviolet detection Methods 0.000 description 2
- MWOOGOJBHIARFG-UHFFFAOYSA-N vanillin Chemical compound COC1=CC(C=O)=CC=C1O MWOOGOJBHIARFG-UHFFFAOYSA-N 0.000 description 2
- 229940117960 vanillin Drugs 0.000 description 2
- FGQOOHJZONJGDT-UHFFFAOYSA-N vanillin Natural products COC1=CC(O)=CC(C=O)=C1 FGQOOHJZONJGDT-UHFFFAOYSA-N 0.000 description 2
- 235000012141 vanillin Nutrition 0.000 description 2
- 235000013618 yogurt Nutrition 0.000 description 2
- 206010001557 Albinism Diseases 0.000 description 1
- 206010012289 Dementia Diseases 0.000 description 1
- 239000004201 L-cysteine Substances 0.000 description 1
- 235000013878 L-cysteine Nutrition 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 208000018737 Parkinson disease Diseases 0.000 description 1
- 244000137852 Petrea volubilis Species 0.000 description 1
- GUWKQWHKSFBVAC-UHFFFAOYSA-N [C].[Au] Chemical compound [C].[Au] GUWKQWHKSFBVAC-UHFFFAOYSA-N 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000012491 analyte Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 239000013626 chemical specie Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 229960002433 cysteine Drugs 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000003113 dilution method Methods 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000008204 material by function Substances 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052961 molybdenite Inorganic materials 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 235000016709 nutrition Nutrition 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001151 other effect Effects 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910001923 silver oxide Inorganic materials 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
- 208000024891 symptom Diseases 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 150000003668 tyrosines Chemical class 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/308—Electrodes, e.g. test electrodes; Half-cells at least partially made of carbon
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The invention discloses an Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and a preparation method and application thereof. The preparation method of the composite material comprises the following steps: adding copper chloride dihydrate and thiourea into a mixed solution of deionized water and N-N-dimethylformamide, magnetically stirring, and reacting in a reaction kettle to obtain CuS microspheres; dispersing CuS microspheres in deionized water, adding glucose under stirring to obtain a CuS dispersion liquid; adding the prepared silver-ammonia solution into the CuS dispersion liquid, stirring, standing, separating and washing a product to obtain the Ag-CuS core-shell microspheres; and adding the Ag-CuS core-shell microspheres into N, N-dimethylformamide dispersed nitrogen-doped graphene to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material. The chemically modified electrode prepared from the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material can be used for quickly detecting tyrosine in food, and has the advantages of low detection limit, good stability, simplicity and convenience in operation and the like.
Description
Technical Field
The invention relates to the technical field of material preparation and electrochemical detection, in particular to a nitrogen-doped graphene composite material loaded by Ag-CuS core-shell microspheres and a preparation method and application thereof.
Background
Tyrosine is an important nutritional amino acid, plays an important role in metabolism, growth and development of people and other animals, and is widely applied to industries such as food, feed, medicine, chemical engineering and the like. The abnormality of tyrosine content has direct relation with some diseases of human body, such as dementia and Parkinson's disease caused by high tyrosine content, and doubtful symptoms, depression, albinism, alkaliuria and the like caused by tyrosine deficiency. Therefore, the method for accurately determining tyrosine, which is simple, convenient, rapid and economic, has great practical significance and scientific value. The current methods for detecting tyrosine mainly comprise methods such as high performance liquid chromatography, fluorescence detection method, mass spectrometry detection method, ultraviolet detection method, capillary electrophoresis amperometric detection method, laser-induced fluorescence detection method, gas chromatography, ion exchange chromatography and the like. However, these methods suffer from drawbacks such as long analysis time, high cost, high sample pre-treatment requirements, etc. making them unsuitable for routine analysis and field testing. In recent years, electrochemical techniques have become the most attractive method for measuring tyrosine due to their advantages of high sensitivity, high accuracy, simple operation, fast analysis speed, low cost, etc. In the construction process of the electrochemical detection method, because the bare glassy carbon electrode has low electrocatalytic activity and weak electrochemical response to an analyte, the key for developing a new electrochemical detection method is to prepare a nano composite material with excellent electrocatalytic performance for modification of a working electrode so as to improve the response performance of electrochemical detection. Tyrosine is an oxidizable amino acid, and has obvious electrochemical signal enhancement on various modified electrodes, for example, electrode materials for tyrosine detection are recently reported as follows: two-dimensional MoS2Carbon gold electrode (detection range 0-100 μ M, detection limit 0.5 μ M, Sensors)&Actuators:B.Chemical 2020,303:127229)、Nd2O3Graphene (detection range 0.1 ℃; E)120 μ M, detection limit of 0.03 μ M, Talanta 2020,206:120176), L-cysteine electropolymerized film (detection range of 3.5-96 μ M, detection limit of 1.1 μ M, Materials Science&Engineering C2019, 98: 496-502), electrically reduced graphene (detection range of 0.8-60 μ M, detection limit of 0.07 μ M, Analytical Methods 2015,7(22): 9535-9541), and the like. However, the electrochemical detection methods constructed by these functional materials have the problems of narrow detection range, high detection limit and poor stability, and are not favorable for accurate determination of tyrosine in actual samples. Therefore, the development of an electrode modification material with wide detection range, low detection limit and strong stability for the electrochemical sensing of tyrosine has important application value.
Disclosure of Invention
The invention aims to solve the primary technical problems that in order to overcome the problems of narrow detection range and higher detection limit of a chemically modified electrode for detecting tyrosine in the prior art, the invention provides a preparation method of an Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material; the modified electrode prepared from the material has a wider detection range and an extremely low detection limit for the detection of tyrosine.
The invention aims to solve another technical problem of providing a nitrogen-doped graphene composite material modified electrode loaded by Ag-CuS core-shell microspheres.
The invention further aims to solve the technical problem of providing the application of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode in detecting the tyrosine content in food.
The technical problem to be solved by the invention is realized by the following technical scheme:
a preparation method of a nitrogen-doped graphene composite material loaded by Ag-CuS core-shell microspheres comprises the following steps:
(1) synthesizing CuS microspheres: weighing 0.3-0.5 mmol of copper chloride dihydrate and 0.8-1.2 mmol of thiourea, adding 7-8 mL of deionized water and 7-8 mL of N, N-dimethylformamide, stirring for 30-60 min, transferring the mixed solution to a hydrothermal reaction kettle, placing the reaction kettle in an oven for constant temperature reaction at 160-180 ℃ for 5-8 hours, and after the reaction is completed, separating and washing the product to obtain CuS microspheres;
(2) preparing a CuS microsphere dispersion liquid: dispersing the obtained CuS microspheres in 4-6 mL of water, and adding 0.7-0.8 g of glucose under the stirring condition to obtain a CuS microsphere dispersion liquid;
(3) preparing a silver ammonia solution: 0.08 to 0.12g of AgNO3Dissolving the silver-ammonia solution in 0.8-1.2 mL of water, and adding 0.5-0.6 mol/L of ammonia water solution until the generated precipitate disappears to obtain the silver-ammonia solution;
(4) dropwise adding the prepared silver ammonia solution into the CuS microsphere dispersion liquid, stirring for 30-60 min, standing for 70-100 min, and separating and washing a product to obtain Ag-CuS core-shell microspheres;
(5) and adding 0.4-0.6 mg of Ag-CuS core-shell microspheres into 4-6 mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 0.8-1.2 mg/mL, performing ultrasonic treatment for 50-80 min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material.
Preferably, step (1) is specifically: weighing 0.4mmol of copper chloride dihydrate and 1mmol of thiourea, adding 7.5mL of deionized water and 7.5mL of N, N-dimethylformamide, stirring for 45min, transferring the mixed solution into a hydrothermal reaction kettle, placing the reaction kettle in an oven for reacting for 6 hours at a constant temperature of 170 ℃, and after the reaction is finished, separating and washing the product to obtain the CuS microspheres.
Preferably, the step (2) is specifically: the obtained CuS microspheres were dispersed in 5mL of water, and 0.75g of glucose was added under stirring to obtain a CuS microsphere dispersion.
Preferably, step (3) is specifically: 0.1g of AgNO3Dissolving in 1mL of water, and adding 0.55mol/L ammonia water solution until the generated precipitate disappears to obtain the silver-ammonia solution.
Preferably, step (5) is specifically: and adding 0.5mg of Ag-CuS core-shell microspheres into 5mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 1mg/mL, performing ultrasonic treatment for 60min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material.
The invention also provides the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material prepared by the preparation method.
The invention provides a brand new Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material prepared by a brand new method, which is prepared by attaching silver nanoparticles to CuS microspheres built by nanosheets to form core-shell structure microspheres, and then further loading the microspheres on nitrogen-doped graphene to form the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material; the material is used for modifying the surface of the electrode, so that the detection limit of electrochemical detection can be obviously reduced, the detection range can be widened, and the anti-interference performance can be enhanced.
In the field of electrochemical detection, those skilled in the art will recognize that for the use of nanocomposites to prepare electrodes for the determination of the content of a particular chemical component or species, the inventors are required to prepare different nanocomposites based on the nature of the particular chemical species being determined. The quality of the detection limit, sensitivity, stability, anti-interference performance and other effects of the prepared electrode on the substance to be measured is mainly determined by the preparation method of the nano composite material. The preparation method of the nano composite material mainly comprises the selection of raw materials, the proportion of the raw materials, the reaction conditions of each step and the like. For the nano composite material used as the electrode, the selection and the proportion of raw materials in the preparation method and the difference of reaction conditions of each step can cause the great difference of the electrical properties of the electrode obtained by subsequent preparation, thereby causing the great difference of the effects of detection limit, detection range, sensitivity, stability, anti-interference performance and the like.
Tyrosine has the defects of weak electrocatalytic oxidation signal, incapability of detecting the content of low-concentration tyrosine and the like on an unmodified working electrode. According to the characteristics of tyrosine, in order to obtain a tyrosine detection electrode with a wide detection range and a low detection limit, the inventor obtains the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres through a large number of experiments by continuously adjusting the raw material composition, the proportion and the process parameters in the preparation process, and the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres prepared by the material has excellent electrochemical response performance, can obviously reduce the detection limit of tyrosine in a sample, and improves the linear range, the stability and the anti-interference performance of detection.
The invention also provides a nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres, which takes the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres as an electrode modified material.
Preferably, the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres is prepared by the following method:
ultrasonically dispersing the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material in an organic solvent to obtain an electrode modification solution;
and dropwise adding the electrode modification solution on the surface of the glassy carbon electrode, and drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode.
The invention also provides an application of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode in detection of tyrosine content in food.
Preferably, the detection is performed by differential pulse voltammetry, and the specific method comprises the following steps:
forming a three-electrode system by taking the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres as a working electrode, a platinum electrode as a counter electrode and a saturated calomel electrode as a reference electrode, and connecting the three-electrode system after assembling with an electrochemical workstation to form an electrochemical detection device;
preparing a standard solution and an actual sample solution to be detected;
measuring the oxidation peak current value of tyrosine in different standard solutions by using a differential pulse voltammetry, obtaining a linear equation according to the relation between the oxidation peak current value of tyrosine and the concentration of the tyrosine, measuring the oxidation peak current value of tyrosine in an actual sample solution to be measured by using the differential pulse voltammetry, and converting the tyrosine concentration according to the obtained linear equation to obtain the tyrosine content in the actual sample to be measured;
wherein the linear equation in the range of 0.3-300 mu mol/L is as follows: i.e. ip＝0.0183c+1.9233×10-7(R20.9927), the linear equation is in the range of 300-4000 mu mol/L: i.e. ip＝0.00348c+3.640×10-6(R20.9898), the linear equation is as follows within the range of 4000-7000 mu mol/L: i.e. ip＝0.01124c+2.581×10-5(R20.9855); c in the equation is tyrosine concentration, and the unit is mol/L; i.e. ipThe unit is A for the oxidation peak current value obtained by differential pulse voltammetry;
the detection conditions of the differential pulse voltammetry are as follows: the pH value of the detection base solution is 3.96, the enrichment time is 60s, the potential increment is 4mV, the amplitude is 50mV, the primary pulse width is 0.2s, the secondary pulse width is 0.05s, the sample measurement width is 0.0167s, and the pulse period is 0.5 s.
Has the advantages that: (1) the invention solves the defects of long analysis time, high cost, high sample pretreatment requirement and the like of methods such as a high performance liquid chromatography method, a fluorescence detection method, a mass spectrometry detection method, an ultraviolet detection method, a capillary electrophoresis amperometric detection method, a laser-induced fluorescence detection method, a gas chromatography and an ion exchange chromatography, and provides a brand-new Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material for preparing a modified electrode, which is prepared by a brand-new method; (2) the electrode prepared by the material can be used for quantitatively detecting tyrosine in food, and has the advantages of wide detection range, low detection limit, strong anti-interference performance and the like; (3) the data of the examples show that the prepared electrode has a linear range of 0.3-7000 mu mol/L and a detection limit of 1.0 multiplied by 10 for tyrosine measurement-4The detection range and detection limit of the micro-mol/L electrode are greatly improved compared with those of a chemically modified electrode and an unmodified electrode reported in the prior art, and the obvious progress is achieved; (4) the electrode can be reused after being stored at room temperature for one month, and the peak current can reach more than 95% of the initial value, which shows that the storage stability of the electrode is excellent; (5) the modified electrode prepared by the method has no obvious interference on the detection of tyrosine under the coexistence condition of sodium nitrite, hydrogen peroxide, tryptophan, L-cysteine, paracetamol, tartrazine, vanillin, salbutamol, 5-hydroxytryptamine, caffeic acid, ferric chloride and other substances.
Drawings
Fig. 1 is a scanning electron microscope image of nitrogen-doped graphene (a), a CuS microsphere-loaded nitrogen-doped graphene composite material (B), and an Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material (C); and ultraviolet spectrograms (D) of the CuS microsphere-loaded nitrogen-doped graphene composite material and the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material.
Fig. 2 is an X-ray powder diffraction pattern (a), a photoelectron spectrum (B) and an energy spectrum element analysis pattern (C) of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material.
Fig. 3 is a cyclic voltammogram (a) and a differential pulse voltammogram (B) of a glassy carbon electrode (a), a nitrogen-doped graphene modified electrode (B), a nitrogen-doped graphene composite material (c) loaded by a CuS microsphere and a nitrogen-doped graphene composite material modified electrode (d) loaded by an Ag-CuS core-shell microsphere in a 7mmol/L tyrosine solution.
FIG. 4 is a cyclic voltammetry curve (B) of oxidation peak current values (A) of 1mmol/L tyrosine on a nitrogen-doped graphene composite material modified electrode loaded by Ag-CuS core-shell microspheres at different enrichment times and under different pH values (the pH values of a-i are 9.92-3.05).
Fig. 5 is a differential pulse voltammetry curve (a) obtained by continuously adding tyrosine with different concentrations to an acetic acid base solution (pH 3.96) of a nitrogen-doped graphene composite material modified electrode loaded by an Ag-CuS core-shell microsphere and a linear relationship diagram (B) in different concentration ranges.
Detailed Description
The present invention is further explained below with reference to specific examples, which are not intended to limit the present invention in any way.
Example 1 preparation of nitrogen-doped graphene composite material loaded with Ag-CuS core-shell microspheres
(1) Synthesizing CuS microspheres: weighing 0.4mmol of copper chloride dihydrate and 1mmol of thiourea, adding 7.5mL of deionized water and 7.5mL of N, N-dimethylformamide into a small beaker, magnetically stirring for 45min, transferring the mixed solution into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle into an oven for constant-temperature reaction at 170 ℃ for 6 hours, naturally cooling to room temperature after the reaction is finished, and then centrifuging, and washing the product with absolute ethyl alcohol and deionized water for 3 times respectively to obtain CuS microspheres;
(2) preparing a CuS microsphere dispersion liquid: dispersing the obtained CuS microspheres in 5mL of water, and adding 0.75g of glucose under the condition of vigorous stirring to obtain a CuS microsphere dispersion liquid;
(3) preparing a silver ammonia solution: 0.1g of AgNO3Dissolving in 1mL of water, and slowly adding 0.55mol/L ammonia water solution until the generated precipitate disappears to obtain silver ammonia solution;
(4) dropwise adding the prepared silver ammonia solution into the CuS microsphere dispersion liquid, stirring for 40min, standing for 90min, centrifuging, and washing the product with absolute ethyl alcohol and deionized water for 3 times respectively to obtain Ag-CuS core-shell microspheres;
(5) and adding 0.5mg of Ag-CuS core-shell microspheres into 5mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 1mg/mL, performing ultrasonic treatment for 60min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material.
Comparative example 1 preparation of CuS microsphere-loaded nitrogen-doped graphene composite material
(1) Synthesizing CuS microspheres: weighing 0.4mmol of copper chloride dihydrate and 1mmol of thiourea, adding 7.5mL of deionized water and 7.5mL of N, N-dimethylformamide into a small beaker, magnetically stirring for 45min, transferring the mixed solution into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, placing the reaction kettle into an oven for constant-temperature reaction at 170 ℃ for 6 hours, naturally cooling to room temperature after the reaction is finished, and then centrifuging, and washing the product with absolute ethyl alcohol and deionized water for 3 times respectively to obtain CuS microspheres;
(2) and adding 0.5mg of CuS microspheres into 5mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 1mg/mL, performing ultrasonic treatment for 60min, and performing centrifugal drying to obtain the CuS microsphere-loaded nitrogen-doped graphene composite material.
The difference between the comparative example 1 and the example 1 is that the reaction step of silver ammonia solution and the CuS microspheres is not carried out in the preparation process, and the nitrogen-doped graphene loaded by the CuS microspheres is directly synthesized.
The morphology and optical characteristics of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material prepared in example 1 are as follows: fig. 1 is a scanning electron microscope image of nitrogen-doped graphene (a), a CuS microsphere-loaded nitrogen-doped graphene composite material (B), and an Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material (C); and ultraviolet spectrograms (D) of the CuS microsphere-loaded nitrogen-doped graphene composite material and the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material. It can be seen from fig. 1(a) that the surface with nitrogen-doped graphene has more pronounced wrinkles due to the nitrogen doping, and such a multi-wrinkled surface facilitates its loading with metal particles. Fig. 1(B) shows that the CuS microspheres are loaded on the surface of the nitrogen-doped graphene, and the CuS microspheres are built by the nanosheets, so that the overall appearance of the microspheres also presents a carnation-like structure. FIG. 1(C) shows that a large amount of silver nanoparticles are deposited on the surface of a CuS microsphere through silver mirror reaction to form an Ag-CuS core-shell microsphere, and the Ag-CuS microsphere is successfully loaded on nitrogen-doped graphene to form the composite material to be prepared by the invention; the composite material integrates the large specific surface area and the core-shell structure of graphene, and is beneficial to high dispersibility and stability of surface metal particles, the composite structure is beneficial to effectively improving the electrocatalytic activity of the composite material, and the sensing performance and the stability of the composite material modified electrode are enhanced. As can be seen from fig. 1(D), compared with the ultraviolet pattern of the CuS microsphere-loaded nitrogen-doped graphene composite material, the ultraviolet pattern of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material has an obvious characteristic peak of metallic Ag at a wavelength of 360nm, which confirms that Ag is successfully deposited on the CuS microsphere to form the Ag-CuS core-shell microsphere.
Fig. 2 is an X-ray powder diffraction pattern (a), a photoelectron spectrum (B) and an energy spectrum element analysis pattern (C) of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material. As can be seen from fig. 2A, the X-ray powder diffraction shows diffraction peaks of (101), (102), (103), (006), (110), (108) and (116) planes of copper sulfide; meanwhile, typical diffraction peaks of metal silver or silver oxide at 32.2 °, 38.3 °, 44.5 °, 46.7 °, 54.9 °, 57.2 °, 68.2 ° and 74.8 ° can be seen; a diffraction peak of the graphene appears at 23.2 degrees, which shows that the composite material contains Ag, CuS and nitrogen-doped graphene, and no obvious other peak is seen, thus the prepared material is mainly the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres. As can be seen from the photoelectron spectroscopy and the energy spectroscopy element analysis diagrams of fig. 2B and C, the material prepared in this example contains elements of C, O, N, Cu, S and Ag, and it can be seen from the measurement of the photoelectron spectroscopy that the atomic percentage contents of these elements are 72.92%, 23.48%, 0.68%, 0.82%, 1.07% and 1.02%, respectively. The characterization method proves the successful preparation of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material.
Example 2 preparation of nitrogen-doped graphene composite material modified electrode loaded with Ag-CuS core-shell microspheres
Using 0.3 μm and 0.05 μm Al2O3Polishing a glassy carbon electrode (the diameter of which is 3mm) on sand paper by using the powder, grinding the glassy carbon electrode into a smooth mirror surface, then ultrasonically cleaning the glassy carbon electrode for 5min by using dilute nitric acid, acetone and distilled water in a ratio of 1:1 in sequence, and then baking the glassy carbon electrode under an infrared lamp for standby application to obtain the well-treated glassy carbon electrode. Then, 1mg of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material prepared in the example 1 is added into 3mL of N, N-dimethylformamide, ultrasonic dispersion is carried out for 10min to obtain a dispersion liquid of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material, 7 μ L of the dispersion liquid is dropwise added on the surface of the treated glassy carbon electrode, and the surface is baked under the irradiation of an infrared lamp to obtain the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material modified electrode (namely, the chemical modified electrode for detecting tyrosine).
For comparison, the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres is replaced by the nitrogen-doped graphene composite material loaded by the nitrogen-doped graphene in the step (5) in example 1 and the nitrogen-doped graphene composite material loaded by the CuS microspheres prepared in comparative example 1 by the above method, so as to prepare the nitrogen-doped graphene modified electrode and the nitrogen-doped graphene composite material modified electrode loaded by the CuS microspheres.
Example 3 detection Performance of Nitrogen-doped graphene composite modified electrode loaded with Ag-CuS core-shell microspheres
In this example, each modified electrode prepared in example 2 was used as an experimental object, and a platinum counter electrode and a saturated calomel reference electrode were combined to form a three-electrode system, which was connected to a CHI660 electrochemical workstation (shanghai chenhua instruments ltd) to perform electrochemical performance detection.
(1) Comparison of electrocatalytic oxidation performances of different electrodes on tyrosine
Using a glassy carbon electrode, a nitrogen-doped graphene modified electrode, a CuS microsphere-loaded nitrogen-doped graphene composite modified electrode, and the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite modified electrode prepared in example 2, a cyclic voltammogram and a differential pulse voltammogram of 7mmol/L tyrosine in an acetic acid base solution with a pH of 3.96 are measured, which is specifically shown in fig. 3. As can be seen from fig. 3A, tyrosine has an unobvious oxidation peak on the bare glassy carbon electrode, while an oxidation reduction peak of the modified material itself appears on the modified electrode, and the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres has oxidation peaks of Ag and CuS at about 0.0V and 0.2V, respectively, and has a reduction peak of Ag-CuS at about-0.1V, which indicates that the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres is successfully modified on the surface of the glassy carbon electrode. More importantly, the three modified electrodes have obvious tyrosine oxidation peaks at about 0.9V, and particularly, the oxidation peak current of the tyrosine on the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microsphere is the largest, so that the modified electrode has the best electrocatalytic oxidation effect on the tyrosine. As can be seen from fig. 3B, the current response of tyrosine on the glassy carbon electrode is very weak, while a significant current response signal appears on the modified electrode. Particularly, on the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres, the current response signal is most obvious, the oxidation peak current on the modified electrode is about 45 muA, and the oxidation peak current values on the glassy carbon electrode, the nitrogen-doped graphene modified electrode and the nitrogen-doped graphene composite material modified electrode loaded by the CuS microspheres are only 0.6 muA, 7.5 muA and 24 muA. Under the condition that the concentration of tyrosine is increased consistently, compared with other electrodes, the current response of the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres is maximum, the current value of the nitrogen-doped graphene composite material modified electrode is 75 times that of an unmodified glassy carbon electrode and is 6 times and 1.9 times that of other two comparative modified electrodes, and the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres has the best electrocatalytic oxidation effect and detection sensitivity on tyrosine, so that the detection limit of tyrosine is reduced, and the detection range of tyrosine is widened.
The operating conditions set by the cyclic voltammetry are as follows: the sweeping speed is 0.05V/s; the potential range is-1.0 to 1.2V.
The detection conditions of the differential pulse voltammetry are as follows: the pH value of the detection base solution is 3.96, the enrichment time is 60s, the potential increment is 4mV, the amplitude is 50mV, the primary pulse width is 0.2s, the secondary pulse width is 0.05s, the sample measurement width is 0.0167s, and the pulse period is 0.5 s.
(2) The Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material prepared by the invention has electrochemical response performance on tyrosine under the conditions of different enrichment times and pH values
The oxidation peak current change condition of tyrosine in the base solution with different enrichment time and pH value is investigated by using differential pulse voltammetry in a three-electrode system with the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode prepared in the embodiment 2 as a working electrode. As can be seen from FIG. 4A, the enrichment time is in the range of 2-120 s, the tyrosine oxidation peak increases and then decreases with the increase of the enrichment time, the maximum current value of the tyrosine oxidation peak appears at 60s, and then the maximum current value of the tyrosine oxidation peak slowly decreases with the increase of the enrichment time, so that the optimal enrichment time of tyrosine on the electrode of the invention is 60 s. As can be seen from fig. 4B, tyrosine has a relatively obvious oxidation peak within a pH range of 9.92 to 3.05, the peak current increases first and then decreases with decreasing pH, and the peak current reaches its maximum value when the pH is 3.96, which indicates that the modified electrode prepared by the present invention has the best electrochemical detection effect on tyrosine under a pH of 3.96.
The detection conditions of the differential pulse voltammetry are as follows: potential increment is 4mV, amplitude is 50mV, primary pulse width is 0.2s, secondary pulse width is 0.05s, sample measurement width is 0.0167s, and pulse period is 0.5 s.
(3) The Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material prepared by the invention has the electrochemical detection performance on tyrosine
Preparing a series of tyrosine solutions with the concentration of 0.3-7000 mu mol/L by 0.01mol/L of tyrosine and using an acetic acid buffer solution with the pH value of 3.96 through a dilution method, adjusting the tyrosine with the series of concentrations to the optimal pH value by using a pH meter, and inspecting the nitrogen-doped graphene composite material modified electrode loaded on the Ag-CuS core-shell microsphere in a series of electrodes through a pulse voltammetry methodListing electrochemical detection performance in different concentrations of tyrosine solution. FIG. 5A shows the result of differential pulse voltammetry, and FIG. 5B is obtained by plotting the oxidation peak current value and the tyrosine concentration of FIG. 5A. It can be seen from FIG. 5B that the three-step linear relationship is formed in the concentration range of 0.3-7000. mu. mol/L, wherein the linear equation in the range of 0.3-300. mu. mol/L is: i.e. ip＝0.0183c+1.9233×10-7(R20.9927), the linear equation is in the range of 300-4000 mu mol/L: i.e. ip＝0.00348c+3.640×10-6(R20.9898), the linear equation is as follows within the range of 4000-7000 mu mol/L: i.e. ip＝0.01124c+2.581×10-5(R20.9855); c in the equation is tyrosine concentration, and the unit is mol/L; i.e. ipThe oxidation peak current value obtained by differential pulse voltammetry is represented by A. In acetic acid base solution containing tyrosine standard solution with pH of 3.96, differential pulse voltammetry measurement is carried out under the condition of keeping pH value unchanged without diluting with acetic acid buffer solution until the concentration is low and no pulse voltammetry signal is recorded as detection limit, and the detection limit is found to be 1.0 × 10 in the process-4μmol/L。
The detection conditions of the differential pulse voltammetry are as follows: potential increment is 4mV, amplitude is 50mV, primary pulse width is 0.2s, secondary pulse width is 0.05s, sample measurement width is 0.0167s, and pulse period is 0.5 s.
(5) The Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode prepared by the method has the anti-interference capacity and stability.
The anti-interference capability of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode prepared by the embodiment in the tyrosine detection process is examined by a differential pulse voltammetry method. Firstly, connecting a three-electrode system consisting of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode prepared by the method, a platinum electrode and a saturated calomel electrode to an electrochemical workstation, and examining the influence of substances such as sodium nitrite, hydrogen peroxide, tryptophan, L-cysteine, paracetamol, tartrazine, vanillin, salbutamol, 5-hydroxytryptamine, caffeic acid and ferric chloride on the determination of tyrosine under the conditions of 60s of enrichment time, 4mV of potential increment, 50mV of amplitude, 0.2s of primary pulse width, 0.05s of secondary pulse width, 0.0167s of sample measurement width and 0.5s of pulse period in acetic acid base solution with the pH of 3.96. Firstly, taking a differential pulse voltammetry curve of 1mmol/L tyrosine solution without adding interfering substances as a blank control, taking 10mL of 1mmol/L tyrosine solution, adding 0.25mL of 1mmol/L interfering substances, setting other conditions unchanged, and repeating the previous operation. The experimental result shows that the error is controlled to be +/-5%, and the influence of the interference substance on the tyrosine can be ignored. The nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres prepared by the invention has good anti-interference capability.
The stability of the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres prepared by the embodiment is examined by a differential pulse voltammetry method. Firstly, connecting a three-electrode system consisting of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode prepared in the embodiment, a platinum electrode and a saturated calomel electrode to an electrochemical workstation, measuring an oxidation peak current response value of 1mmol/L tyrosine under the conditions of potential increment of 4mV, amplitude of 50mV, primary pulse width of 0.2s, secondary pulse width of 0.05s, sample measurement width of 0.0167s and pulse period of 0.5s in acetic acid base solution with pH of 3.96, and then storing for 30 days at room temperature and measuring the oxidation peak current response value again under the same conditions. As a result, the current response is maintained above 95% of the initial value after the electrode is stored for 30 days in a room temperature environment, which indicates that the chemically modified electrode for detecting tyrosine provided by the invention has excellent stability.
EXAMPLE 4 method for detecting tyrosine in actual samples
(1) Forming a three-electrode system by taking the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres as a working electrode, a platinum electrode as a counter electrode and a saturated calomel electrode as a reference electrode, and connecting the three-electrode system to an electrochemical workstation;
(2) preparing a sample solution to be actually detected;
(3) measuring the oxidation peak current value of tyrosine in the sample by using a differential pulse voltammetry method, and converting out the tyrosine concentration according to a linear equation (as described in example 3) so as to obtain the content of tyrosine in the actual sample; the detection conditions of the differential pulse voltammetry are as follows: the pH value of the detection base solution is 3.96, the enrichment time is 60s, the potential increment is 4mV, the amplitude is 50mV, the primary pulse width is 0.2s, the secondary pulse width is 0.05s, the sample measurement width is 0.0167s, and the pulse period is 0.5 s.
EXAMPLE 5 detection of tyrosine in actual samples
Taking a certain brand of yogurt, obtaining supernatant through ultrasound and centrifugation, taking 1mL of supernatant liquid in a 100mL volumetric flask by using a pipette, and fixing the volume to 100mL by using an acetic acid buffer solution with the pH value of 3.96 as an actual sample to be detected. Forming a three-electrode system by taking the nitrogen-doped graphene composite material modified electrode loaded by the Ag-CuS core-shell microspheres as a working electrode, a platinum electrode as a counter electrode and a saturated calomel electrode as a reference electrode, and connecting the three-electrode system to an electrochemical workstation; and (3) determining the content of tyrosine in the sample by using differential pulse voltammetry. Taking 10mL of an actual sample, measuring tyrosine in the actual sample by adopting a differential pulse voltammetry method under the conditions of enrichment time of 60s, potential increment of 4mV, amplitude of 50mV, primary pulse width of 0.2s, secondary pulse width of 0.05s, sample measurement width of 0.0167s and pulse period of 0.5s, then sequentially adding 1mL of tyrosine standard solutions of 0.1mmol/L, 1mL0.3mmol/L and 1mL0.7mmol/L, and observing the peak appearance of tyrosine under the same conditions. The peak current shows a linear increasing trend along with the gradual addition of the standard solution, which indicates that the modified electrode prepared by the invention can be used for detecting tyrosine in an actual sample. The corresponding concentration value of tyrosine in the measured sample is found from the obtained oxidation value and linear relationship chart (see the description in example 3). The tyrosine content of the tested yogurt sample is 5.6 mu mol/L according to the detection method.
Claims (10)
1. A preparation method of an Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material is characterized by comprising the following steps:
(1) synthesizing CuS microspheres: weighing 0.3-0.5 mmol of copper chloride dihydrate and 0.8-1.2 mmol of thiourea, adding 7-8 mL of deionized water and 7-8 mL of N, N-dimethylformamide, stirring for 30-60 min, transferring the mixed solution to a hydrothermal reaction kettle, placing the reaction kettle in an oven for constant temperature reaction at 160-180 ℃ for 5-8 hours, and after the reaction is completed, separating and washing the product to obtain CuS microspheres;
(2) preparing a CuS microsphere dispersion liquid: dispersing the obtained CuS microspheres in 4-6 mL of water, and adding 0.7-0.8 g of glucose under the stirring condition to obtain a CuS microsphere dispersion liquid;
(3) preparing a silver ammonia solution: 0.08 to 0.12g of AgNO3Dissolving the silver-ammonia solution in 0.8-1.2 mL of water, and adding 0.5-0.6 mol/L of ammonia water solution until the generated precipitate disappears to obtain the silver-ammonia solution;
(4) dropwise adding the prepared silver ammonia solution into the CuS microsphere dispersion liquid, stirring for 30-60 min, standing for 70-100 min, and separating and washing a product to obtain Ag-CuS core-shell microspheres;
(5) and adding 0.4-0.6 mg of Ag-CuS core-shell microspheres into 4-6 mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 0.8-1.2 mg/mL, performing ultrasonic treatment for 50-80 min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material.
2. The preparation method of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material according to claim 1, which is characterized in that,
the step (1) is specifically as follows: weighing 0.4-0.5 mmol of copper chloride dihydrate and 1-1.2 mmol of thiourea, adding 7.5-8 mL of deionized water and 7.5-8 mL of N, N-dimethylformamide, stirring for 45-60 min, transferring the mixed solution to a hydrothermal reaction kettle, placing the reaction kettle in an oven for reacting for 6-8 hours at a constant temperature of 170-180 ℃, and after the reaction is completed, separating and washing the product to obtain CuS microspheres;
most preferably, step (1) is specifically: weighing 0.4mmol of copper chloride dihydrate and 1mmol of thiourea, adding 7.5mL of deionized water and 7.5mL of N, N-dimethylformamide, stirring for 45min, transferring the mixed solution into a hydrothermal reaction kettle, placing the reaction kettle in an oven for reacting for 6 hours at a constant temperature of 170 ℃, and after the reaction is finished, separating and washing the product to obtain the CuS microspheres.
3. The preparation method of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material according to claim 1, which is characterized in that,
the step (2) is specifically as follows: dispersing the obtained CuS microspheres in 5-6 mL of water, and adding 0.75-0.8 g of glucose under the stirring condition to obtain a CuS microsphere dispersion liquid;
most preferably, step (2) is specifically: the obtained CuS microspheres were dispersed in 5mL of water, and 0.75g of glucose was added under stirring to obtain a CuS microsphere dispersion.
4. The preparation method of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material according to claim 1, wherein the step (3) is specifically as follows: 0.1g of AgNO3Dissolving in 1mL of water, and adding 0.55mol/L ammonia water solution until the generated precipitate disappears to obtain the silver-ammonia solution.
5. The preparation method of the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material according to claim 1, which is characterized in that,
the step (5) is specifically as follows: adding 0.5-0.6 mg of Ag-CuS core-shell microspheres into 5-6 mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 1-1.2 mg/mL, performing ultrasonic treatment for 60-80 min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material;
most preferably, step (5) is specifically: and adding 0.5mg of Ag-CuS core-shell microspheres into 5mL of N, N-dimethylformamide dispersed nitrogen-doped graphene with the concentration of 1mg/mL, performing ultrasonic treatment for 60min, and performing centrifugal drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material.
6. The Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material prepared by the preparation method of any one of claims 1 to 5.
7. A nitrogen-doped graphene composite material modified electrode loaded by Ag-CuS core-shell microspheres is characterized in that the nitrogen-doped graphene composite material loaded by the Ag-CuS core-shell microspheres in claim 6 is used as an electrode modified material.
8. The Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode according to claim 7 is characterized by being prepared by the following method:
ultrasonically dispersing the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material in an organic solvent to obtain an electrode modification solution;
and dropwise adding the electrode modification solution on the surface of the glassy carbon electrode, and drying to obtain the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode.
9. The application of the Ag-CuS core-shell microsphere-loaded nitrogen-doped graphene composite material modified electrode in detecting the tyrosine content in food according to claim 7 or 8.
10. The use according to claim 9, wherein the detection is performed using differential pulse voltammetry, the method comprising the steps of:
forming a three-electrode system by using the Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material modified electrode as a working electrode, a platinum electrode as a counter electrode and a saturated calomel electrode as a reference electrode, and connecting the assembled three-electrode system with an electrochemical workstation to form an electrochemical detection device;
preparing a standard solution and an actual sample solution to be detected;
measuring the oxidation peak current value of tyrosine in different standard solutions by using a differential pulse voltammetry, obtaining a linear equation according to the relation between the oxidation peak current value of tyrosine and the concentration of the tyrosine, measuring the oxidation peak current value of tyrosine in an actual sample solution to be measured by using the differential pulse voltammetry, and converting the tyrosine concentration according to the obtained linear equation to obtain the tyrosine content in the actual sample to be measured;
wherein the linear equation in the range of 0.3-300 mu mol/L is as follows: i.e. ip＝0.0183c+1.9233×10-7(R20.9927), the linear equation is in the range of 300-4000 mu mol/L: i.e. ip＝0.00348c+3.640×10-6(R20.9898), the linear equation is as follows within the range of 4000-7000 mu mol/L: i.e. ip＝0.01124c+2.581×10-5(R20.9855); c in the equation is tyrosine concentration, and the unit is mol/L; i.e. ipThe unit is A for the oxidation peak current value obtained by differential pulse voltammetry;
the detection conditions of the differential pulse voltammetry are as follows: the pH value of the detection base solution is 3.96, the enrichment time is 60s, the potential increment is 4mV, the amplitude is 50mV, the primary pulse width is 0.2s, the secondary pulse width is 0.05s, the sample measurement width is 0.0167s, and the pulse period is 0.5 s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010108443.8A CN111272841B (en) | 2020-02-21 | 2020-02-21 | Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010108443.8A CN111272841B (en) | 2020-02-21 | 2020-02-21 | Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111272841A true CN111272841A (en) | 2020-06-12 |
| CN111272841B CN111272841B (en) | 2022-07-08 |
Family
ID=70997182
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010108443.8A Active CN111272841B (en) | 2020-02-21 | 2020-02-21 | Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111272841B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113945617A (en) * | 2021-09-24 | 2022-01-18 | 合肥天一生物技术研究所有限责任公司 | Screen printing electrode for detecting content of vitamin B6 in blood plasma |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109613090A (en) * | 2018-11-14 | 2019-04-12 | 衡阳师范学院 | Sea urchin type is Prussian blue-palladium core-shell structure load nitrogen-doped graphene nanocomposite and its electrode being prepared and application |
| CN110412095A (en) * | 2019-07-26 | 2019-11-05 | 衡阳师范学院 | A kind of load flower ball-shaped copper sulfide-palladium core-shell structure nitrogen-doped graphene composite material and preparation method and application |
| CN110426433A (en) * | 2019-08-23 | 2019-11-08 | 衡阳师范学院 | A kind of the nitrogen-doped graphene composite material and preparation method and application of silver-Prussian blue load |
-
2020
- 2020-02-21 CN CN202010108443.8A patent/CN111272841B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109613090A (en) * | 2018-11-14 | 2019-04-12 | 衡阳师范学院 | Sea urchin type is Prussian blue-palladium core-shell structure load nitrogen-doped graphene nanocomposite and its electrode being prepared and application |
| CN110412095A (en) * | 2019-07-26 | 2019-11-05 | 衡阳师范学院 | A kind of load flower ball-shaped copper sulfide-palladium core-shell structure nitrogen-doped graphene composite material and preparation method and application |
| CN110426433A (en) * | 2019-08-23 | 2019-11-08 | 衡阳师范学院 | A kind of the nitrogen-doped graphene composite material and preparation method and application of silver-Prussian blue load |
Non-Patent Citations (1)
| Title |
|---|
| JUNHUA LI ET.AL: "Morphology-controlled electrochemical sensing properties of CuS crystals for tartrazine and sunset yellow", 《SENSORS AND ACTUATORS B: CHEMICAL》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113945617A (en) * | 2021-09-24 | 2022-01-18 | 合肥天一生物技术研究所有限责任公司 | Screen printing electrode for detecting content of vitamin B6 in blood plasma |
| CN113945617B (en) * | 2021-09-24 | 2023-11-21 | 合肥天一生物技术研究所有限责任公司 | Screen printing electrode for detecting vitamin B6 content in blood plasma |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111272841B (en) | 2022-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ensafi et al. | Non-enzymatic glucose electrochemical sensor based on silver nanoparticle decorated organic functionalized multiwall carbon nanotubes | |
| Yang et al. | Hydrogen peroxide and glucose biosensor based on silver nanowires synthesized by polyol process | |
| Ibupoto et al. | Effect of urea on the morphology of Co3O4 nanostructures and their application for potentiometric glucose biosensor | |
| Zhang et al. | An enzyme-free hydrogen peroxide sensor based on Ag/FeOOH nanocomposites | |
| Ensafi et al. | Nickel-ferrite oxide decorated on reduced graphene oxide, an efficient and selective electrochemical sensor for detection of furazolidone | |
| Rao et al. | Highly improved sensing of dopamine by using glassy carbon electrode modified with MnO 2, graphene oxide, carbon nanotubes and gold nanoparticles | |
| Ghanei-Motlagh et al. | Stripping voltammetric detection of copper ions using carbon paste electrode modified with aza-crown ether capped gold nanoparticles and reduced graphene oxide | |
| Zhang et al. | A Cu 2 O/Cu/carbon cloth as a binder-free electrode for non-enzymatic glucose sensors with high performance | |
| CN110426433B (en) | silver-Prussian blue loaded nitrogen-doped graphene composite material and preparation method and application thereof | |
| Taheri et al. | Sensitive and selective determination of Cu2+ at d-penicillamine functionalized nano-cellulose modified pencil graphite electrode | |
| Ensafi et al. | Electrochemical sensing of flutamide contained in plasma and urine matrices using NiFe2O4/rGO nanocomposite, as an efficient and selective electrocatalyst | |
| CN110412095B (en) | Nitrogen-doped graphene composite material loaded with flower-ball-shaped copper sulfide-palladium core-shell structure and preparation method and application thereof | |
| Hamtak et al. | Sensitive nonenzymatic electrochemiluminescence determination of hydrogen peroxide in dental products using a polypyrrole/polyluminol/titanium dioxide nanocomposite | |
| Liu et al. | An ultrasensitive immunosensor based on cellulose nanofibrils/polydopamine/Cu-Ag nanocomposite for the detection of AFP | |
| CN110039043B (en) | Three-dimensional copper @ carbon core-shell nanoparticle, and preparation method and application thereof | |
| Mahmoodi et al. | Fabrication of electrochemical sensor based on CeO2− SnO2 nanocomposite loaded on Pd support for determination of nitrite at trace levels | |
| CN111272841B (en) | Ag-CuS core-shell microsphere loaded nitrogen-doped graphene composite material and preparation method and application thereof | |
| Amini et al. | Application of an electrochemical sensor using copper oxide nanoparticles/polyalizarin yellow R nanocomposite for hydrogen peroxide | |
| Ensafi et al. | Developing a sensitive DNA biosensor for the detection of flutamide using electrochemical method | |
| Li et al. | Disposable Sandwich‐type Electrochemical Sensor for Selective Detection of Glucose Based on Boronate Affinity | |
| CN111060573A (en) | CoFe Prussian blue analogue modified electrode and application thereof in simultaneous determination of dopamine and 5-hydroxytryptamine contents | |
| Figiela et al. | Highly Sensitive, Fast Response and Selective Glucose Detection Based on CuO/Nitrogen‐doped Carbon Non‐enzymatic Sensor | |
| Sharma et al. | Non‐enzymatic electrochemical oxidation based on AuNP/PPy/rGO nanohybrid modified glassy carbon electrode as a sensing platform for oxalic acid | |
| Naik et al. | Green and sustainable synthesis of CaO nanoparticles: Its solicitation as a sensor material and electrochemical detection of urea | |
| Li et al. | A novel strategy of electrochemically treated ZrOCl2 doped carbon paste electrode for sensitive determination of daidzein |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20200612 Assignee: Hunan Songyitang Technology Co.,Ltd. Assignor: Hengyang Normal University Contract record no.: X2023980047920 Denomination of invention: A nitrogen doped graphene composite material loaded with Ag CuS core-shell microspheres and its preparation method and application Granted publication date: 20220708 License type: Common License Record date: 20231123 |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| OL01 | Intention to license declared | ||
| OL01 | Intention to license declared |