CN110658249A - Application of graphene-cerium dioxide composite material catalyst - Google Patents
Application of graphene-cerium dioxide composite material catalyst Download PDFInfo
- Publication number
- CN110658249A CN110658249A CN201911012264.8A CN201911012264A CN110658249A CN 110658249 A CN110658249 A CN 110658249A CN 201911012264 A CN201911012264 A CN 201911012264A CN 110658249 A CN110658249 A CN 110658249A
- Authority
- CN
- China
- Prior art keywords
- graphene
- tryptophan
- composite material
- cerium dioxide
- dioxide 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.)
- Pending
Links
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
- G01N27/416—Systems
- G01N27/48—Systems using polarography, i.e. measuring changes in current under a slowly-varying voltage
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/10—Heat treatment in the presence of water, e.g. steam
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analytical Chemistry (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Thermal Sciences (AREA)
- Catalysts (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
The invention relates to an application of a graphene-cerium dioxide composite material catalyst. The graphene-cerium dioxide composite material is used for detecting tryptophan and has the characteristics of high sensitivity, good stability and reusability.
Description
Technical Field
The invention belongs to the field of application of catalyst materials in electrochemical detection, and particularly relates to application of a graphene-cerium dioxide composite material catalyst.
Background
In recent years, graphene materials show good and wide application prospects in the fields of catalysis, energy storage electronic devices and the like, and meanwhile, the graphene materials are also greatly concerned in the development of electrochemical sensors as electrode materials. On the other hand, the naturally large specific surface area of graphene makes it an excellent support material for metal or metal oxide catalysts, and has been commonly used in electrochemical sensors, fuel cells, lithium ion batteries and supercapacitors (anal. chem.,2015,87, 989-. The graphene-supported ceria composite material can be prepared by a hydrothermal method (Chinese patent CN102631913B), but the reported preparation method needs to be prepared under high-temperature (>220 ℃) and long-time (>12h) heating conditions, so a method for rapidly preparing the graphene-ceria composite material at a lower temperature needs to be developed.
Tryptophan is one of the essential amino acids required by the human body, and deficiency in the body can cause serious neurological diseases, while maintenance of normal concentration levels of tryptophan in the human body requires dietary supplementation. Therefore, the sensitive detection of the tryptophan content in the food (such as milk) has important significance for the quality control of the food and the maintenance of the human nutrition balance. At present, a method for detecting tryptophan based on an electrochemical sensor needs complicated pretreatment and a complex preparation method, has low sensitivity and is seriously interfered by other substances (electrochim. acta 2011,57, 290-.
Disclosure of Invention
The invention aims to solve the technical problem of providing the application of the graphene-cerium dioxide composite material catalyst so as to overcome the defects that the electrochemical sensor needs complicated pretreatment and complex preparation method for detecting tryptophan in the prior art and has low sensitivity.
The invention provides an application of a graphene-cerium dioxide composite material in tryptophan detection.
The preparation method of the graphene-cerium dioxide composite material comprises the following steps: dispersing graphene oxide and cerium nitrate in deionized water, adjusting the pH value to be alkaline (preferably the pH value is 8-9) by using a sodium hydroxide solution, adding hydrazine hydrate, carrying out hydrothermal reaction at 140 ℃ and 180 ℃ for 4-8h, cooling, centrifuging, washing and drying to obtain the graphene oxide-cerium nitrate deionized water-hydrazine hydrate composite material, wherein the ratio of the graphene oxide to the cerium nitrate to the hydrazine hydrate is 2-3 mg: 8-11 mg: 0.8-1.5 mL: 1-1.5 muL.
The washing is as follows: deionized water and ethanol were washed 3 times each.
The drying comprises the following steps: vacuum drying at 50 deg.C.
The size of the cerium dioxide particles in the graphene-cerium dioxide composite material is 6-10 nm.
The application of the graphene-cerium dioxide composite material in the detection of tryptophan is that the graphene-cerium dioxide composite material is used for constructing an electrochemical sensor and then is used for detecting tryptophan.
The electrochemical sensor constructed by the graphene-cerium dioxide composite material comprises the following components: ultrasonically dispersing the graphene-cerium dioxide composite material in ethanol to obtain a dispersion liquid with the concentration of 1-2 mg/mL, transferring 5-10 mu L of the dispersion liquid to the surface of a glassy carbon electrode, drying to obtain a working electrode, and combining a reference electrode and a counter electrode to construct an electrochemical sensor.
The drying comprises the following steps: and heating and drying by an infrared lamp.
The reference electrode is a saturated calomel electrode; the counter electrode is a platinum wire.
The working concentration range of the electrochemical sensor is 0.2-25 mu M, and the lower detection limit can reach 80 nM.
The detection is carried out in a phosphate buffer solution with the pH value of 7, and the detection method is cyclic voltammetry and differential pulse voltammetry. Firstly, testing a tryptophan standard solution, establishing a standard working curve by taking the concentration as an abscissa and the current intensity as an ordinate, and calculating the concentration of tryptophan in a sample by testing the current intensity of the sample.
The detection voltage range is 0.2V to 1V.
The detection tryptophan is as follows: and detecting the content of tryptophan.
The detection tryptophan is as follows: and detecting tryptophan in the food.
The method for detecting tryptophan in food comprises the following steps: and (4) detecting tryptophan in the milk.
The graphene-cerium dioxide composite material is applied to sensitive detection of tryptophan in a milk sample, the recovery rate is 99.6-100.4%, the stability is good, and the sensing performance is not obviously changed after the graphene-cerium dioxide composite material is stored in air at room temperature for one month.
Advantageous effects
(1) The graphene-cerium dioxide composite material catalyst is rapidly prepared for 4-8h under the hydrothermal reaction condition of lower temperature (140-;
(2) the electrochemical sensor constructed on the basis of the graphene-cerium dioxide composite material can be applied to tryptophan detection in a milk sample, and has the characteristics of high sensitivity, good stability and reusability.
Drawings
FIG. 1 is a graph based on graphene-cerium oxide (RGO-CeO) in example 22) And (3) a linear relation graph between the current intensity and the tryptophan concentration of the electrochemical sensor prepared from the composite material.
FIG. 2 is the graphene-ceria (RGO-CeO) in example 12) Transmission Electron Microscopy (TEM) images of the composite.
FIG. 3 is the graphene-ceria (RGO-CeO) of example 12) X-ray diffraction (XRD) pattern of the composite.
FIG. 4 is a cyclic voltammogram of the response of different electrodes to tryptophan in example 2.
FIG. 5 is a graph based on graphene-cerium oxide (RGO-CeO) in example 22) And (3) a differential pulse voltammogram of an electrochemical sensor prepared from the composite material in response to different concentrations of tryptophan.
FIG. 6 is a graph based on graphene-cerium oxide (RGO-CeO) in example 22) And (3) a response stability change diagram of the electrochemical sensor prepared from the composite material.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
The graphene oxide related to the invention is purchased from Nanjing Xiancheng nanomaterial science and technology Limited, and the chemical reagents such as cerium nitrate are products of chemical reagents Limited of Chinese medicine group.
Example 1
Graphene-cerium oxide (RGO-CeO)2) And (4) preparing the composite material.
100mg of graphene oxide and 400mg of cerium nitrate are dispersed in 40mL of deionized water by ultrasonic treatment for 30 minutes, the pH value is adjusted to 9 by using 0.5M NaOH solution, the solution is transferred to a 100mL hydrothermal reaction kettle, 40 mu L of hydrazine hydrate is added, and the temperature is maintained at 160 ℃ for 6 hours. Cooling to room temperature, centrifuging, washing the obtained solid with deionized water for 3 times, washing with ethanol for 3 times, and drying in a 50 deg.C oven for 24 hr to obtain graphene-cerium dioxide (RGO-CeO)2) A composite material. It is apparent from TEM test (fig. 2) that the ceria nanoparticles have a size of about 10nm and are uniformly dispersed on the graphene sheet in the wrinkled structure. In the XRD spectrum (fig. 3), sharp diffraction peaks at 28.6,33.2,47.5,56.4 and 59.2 ° were observed, which were respectively assigned to CeO2And (100), (200), (220), (311) and (222) crystal planes, while a diffraction peak broader at 24.6 ° is assigned to the (002) crystal plane of graphene (fig. 3). These results indicate that the graphene-ceria composite was successfully prepared. In the above reaction, graphene oxide or cerium nitrate is used as a precursor to prepare graphene (RGO) or cerium dioxide (CeO)2) Catalyst material for comparison with composite properties.
Example 2
Preparing an electrochemical sensor and applying the electrochemical sensor to tryptophan detection.
Graphene-cerium oxide (RGO-CeO) prepared in example 1 was weighed2) Uniformly dispersing 2mg of composite material catalyst in 1mL of absolute ethyl alcohol by ultrasonic wave, transferring 7 mu L of dispersed liquid drop on the surface of a glassy carbon electrode by using a liquid transfer gun, and drying by using an infrared lamp to obtain a working electrode (RGO-CeO)2and/GCE), and forming a three-electrode system with a saturated calomel electrode and a platinum wire electrode to construct the electrochemical sensor. An electrochemical scan of a tryptophan standard solution (20 μ M) was performed using cyclic voltammetry with a phosphate buffer solution (pH 7) as the assay medium at a voltage range of 0.2V to 1V. And glassy carbon electrode (RGO/GCE or CeO) modified by bare Glassy Carbon Electrode (GCE), graphene or cerium dioxide respectively2/GCE) (preparation method and aboveSame) as the working electrode, it can be seen that the composite catalyst has significantly enhanced current intensity (fig. 4), indicating that the graphene-ceria (RGO-CeO) prepared according to the present invention has significantly enhanced current intensity2) The composite material catalyst can obviously improve the detection sensitivity.
Electrochemical titration is carried out by differential pulse voltammetry, and the peak current intensity is gradually increased along with the increase of the tryptophan concentration (figure 5), the tryptophan concentration and the peak current intensity are in a linear relation in the range of 0.2-25 mu M, the linear regression coefficient is 0.9989, the linear regression equation is that y is 0.5635x +0.1178, y represents the current intensity (mu A), and x represents the tryptophan concentration (mu M), and the tryptophan concentration can be calculated by measuring the current intensity according to the working curve (figure 1). The lower limit of the detection in the invention can reach 80nM, which is lower than the detection limit reported in the literature of 810nM (electrochim. acta 2011,57,290-296) and 210nM (sens. activators B: chem.2018,259,433-442), and the electrochemical sensor has higher sensitivity.
Additionally, a working electrode (RGO-CeO)2/GCE) was left in the air for one month, and electrochemical detection of a tryptophan solution (20 μ M) was performed every 5 days using differential pulse voltammetry, and the current intensity was recorded (fig. 6), and it was found that the current intensity had a small decay change, indicating that the electrochemical sensing system had good stability and reusability.
Example 3
Determination of tryptophan concentration in milk samples.
After the commercial boxed normal-temperature milk is centrifuged and separated at 15000 rpm, 1mL of supernatant is diluted by 5mL of PBS (pH 7) buffer solution, the current value y is directly measured to be 0.96 mu A according to the steps in example 2, the current value y is substituted into a linear regression equation y of 0.5635x +0.1178, the tryptophan content x in the milk can be calculated to be 1.5 mu M, samples respectively added with (1-3 mu M) tryptophan standard samples are detected by a standard addition method, the obtained recovery rate is between 99.6-100.4%, and the result is satisfactory, which indicates that the electrochemical sensing system can be applied to sensitively detecting the tryptophan in an actual milk sample.
In the prior art, tryptophan is electrochemically determined by using an organic polymer-carbon nanotube (electrochemical. acta 2011,57,290-296) or NiO-organic polymer-carbon nanotube (sens. activators B: chem.2018,259,433-442) composite material catalyst, the used method is a differential pulse voltammetry, the detection limit is 810nM or 210nM respectively, and the detection limit is higher than 80nM in the invention, so that the electrochemical sensor has the advantage of higher sensitivity.
Claims (10)
1. An application of a graphene-cerium dioxide composite material in tryptophan detection.
2. The use according to claim 1, wherein the graphene-ceria composite is prepared by a method comprising: dispersing graphene oxide and cerium nitrate in deionized water, adjusting the pH value to be alkaline by using a sodium hydroxide solution, adding hydrazine hydrate, carrying out hydrothermal reaction at the temperature of 140 ℃ and 180 ℃ for 4-8h, cooling, centrifuging, washing and drying to obtain the graphene oxide/cerium nitrate/deionized water/hydrazine hydrate composite material, wherein the ratio of the graphene oxide/cerium nitrate/deionized water/hydrazine hydrate is 2-3 mg/8-11 mg/0.8-1.5 mL/1-1.5 mu L.
3. The use according to claim 1 or 2, wherein the graphene-ceria composite has a ceria particle size of 6-10 nm.
4. The application of the graphene-cerium dioxide composite material in the detection of tryptophan according to claim 1 is characterized in that the graphene-cerium dioxide composite material is used for constructing an electrochemical sensor and then is used for detecting tryptophan.
5. The application of the graphene-cerium dioxide composite material in the construction of the electrochemical sensor according to claim 4, wherein the graphene-cerium dioxide composite material is prepared from the following components in percentage by weight: ultrasonically dispersing the graphene-cerium dioxide composite material in ethanol to obtain a dispersion liquid with the concentration of 1-2 mg/mL, transferring 5-10 mu L of the dispersion liquid to the surface of a glassy carbon electrode, drying to obtain a working electrode, and combining a reference electrode and a counter electrode to construct an electrochemical sensor.
6. The use of claim 4 or 5, wherein the electrochemical sensor operates at a concentration in the range of 0.2-25 μ M with a lower detection limit of up to 80 nM.
7. The use of claim 1 or 4, wherein the detection is performed in phosphate buffered saline at pH 7, and the detection methods are cyclic voltammetry and differential pulse voltammetry.
8. The use of claim 1 or 4, wherein the tryptophan is detected as: and detecting the content of tryptophan.
9. The use of claim 1 or 4, wherein the tryptophan is detected as: and detecting tryptophan in the food.
10. The use of claim 9, wherein the detection of tryptophan in a food product comprises: and (4) detecting tryptophan in the milk.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911012264.8A CN110658249A (en) | 2019-10-23 | 2019-10-23 | Application of graphene-cerium dioxide composite material catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911012264.8A CN110658249A (en) | 2019-10-23 | 2019-10-23 | Application of graphene-cerium dioxide composite material catalyst |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110658249A true CN110658249A (en) | 2020-01-07 |
Family
ID=69041811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911012264.8A Pending CN110658249A (en) | 2019-10-23 | 2019-10-23 | Application of graphene-cerium dioxide composite material catalyst |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110658249A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103611523A (en) * | 2013-11-08 | 2014-03-05 | 南京大学 | Preparation method of high-dispersion lamellar nanometer ceric oxide/graphene composite material |
| CN105255446A (en) * | 2015-11-06 | 2016-01-20 | 安徽理工大学 | Reduced graphene oxide and nano cerium oxide composite microwave absorbing material and preparation method thereof |
| CN105854865A (en) * | 2016-04-10 | 2016-08-17 | 南昌航空大学 | Three-dimensional porous structure graphene-cerium dioxide composite photocatalyst |
| CN106483169A (en) * | 2016-09-18 | 2017-03-08 | 西安交通大学 | A kind of high sensitivity gas sensor nano Ce O2The preparation method of/graphene composite material |
-
2019
- 2019-10-23 CN CN201911012264.8A patent/CN110658249A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103611523A (en) * | 2013-11-08 | 2014-03-05 | 南京大学 | Preparation method of high-dispersion lamellar nanometer ceric oxide/graphene composite material |
| CN105255446A (en) * | 2015-11-06 | 2016-01-20 | 安徽理工大学 | Reduced graphene oxide and nano cerium oxide composite microwave absorbing material and preparation method thereof |
| CN105854865A (en) * | 2016-04-10 | 2016-08-17 | 南昌航空大学 | Three-dimensional porous structure graphene-cerium dioxide composite photocatalyst |
| CN106483169A (en) * | 2016-09-18 | 2017-03-08 | 西安交通大学 | A kind of high sensitivity gas sensor nano Ce O2The preparation method of/graphene composite material |
Non-Patent Citations (2)
| Title |
|---|
| A. MURALI ET AL: "Synthesis of CeO2/reduced graphene oxide nanocomposite for electrochemical determination of ascorbic acid and dopamine and for photocatalytic applications", 《MATERIALS TODAY CHEMISTRY》 * |
| 李春香 等: "电化学还原的氧化石墨烯修饰电极检测Ｌ－色氨酸", 《分析科学学报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhu et al. | Hierarchical flower-like zinc oxide nanosheets in-situ growth on three-dimensional ferrocene-functionalized graphene framework for sensitive determination of epinephrine and its oxidation derivative | |
| Fu et al. | An electrochemical sensor based on reduced graphene oxide and ZnO nanorods-modified glassy carbon electrode for uric acid detection | |
| Li et al. | Synthesis of palladium@ gold nanoalloys/nitrogen and sulphur-functionalized multiple graphene aerogel for electrochemical detection of dopamine | |
| CN109307700B (en) | Method for determining rutin by using cobalt-based metal organic framework material/three-dimensional graphene nanocomposite modified electrode | |
| CN103048363B (en) | Metallic oxide material with mesoporous-macroporous composite structure as well as preparation method and application thereof | |
| CN108732207A (en) | A kind of sensitive material used in formaldehyde examination and preparation method and application | |
| CN106770544A (en) | Ni MOF ultrathin nanometers band, synthetic method and its application | |
| CN109187679B (en) | Electrochemical sensor and preparation method and application thereof | |
| CN110040766B (en) | Preparation method of high-humidity-resistance nano gas-sensitive material and gas-sensitive sensor | |
| CN112798665B (en) | Preparation method and application of copper-based-organic metal framework electrochemical sensor for measuring zearalenone | |
| CN108414589A (en) | Foam-like porous carbon net/nickel nano particle three-dimensional composite and its synthetic method and application | |
| Luan et al. | Ni3S2/ionic liquid-functionalized graphene as an enhanced material for the nonenzymatic detection of glucose | |
| CN113588751B (en) | MXene@CoAl-LDH nano composite membrane modified electrode, preparation method thereof and application of modified electrode in pesticide detection | |
| Niu et al. | Ag@ Ni3 (BTC) 2 microspheres showing high electrochemical activity and their application as supercapacitors and electrochemical sensors | |
| CN112505118B (en) | Electrochemical sensor for detecting glucose and preparation method thereof | |
| Wei et al. | A novel electrochemical sensor based on DUT-67/ZnCo2O4-MWCNTs modified glassy carbon electrode for the simultaneous sensitive detection of dopamine and uric acid | |
| CN109916976B (en) | Preparation method and application of zinc germanate nanorod-modified functionalized graphene composite material | |
| CN103736107B (en) | A kind of magnetic resonance contrast agent with electrochemical sensing function and preparation method thereof | |
| Tan et al. | Production of Ni 7 S 6/NiO hybrids as a highly sensitive amperometric sensor for glucose | |
| CN110887887A (en) | Starch in-vitro rapid digestion detector based on electrochemical glucose sensor and preparation method and application thereof | |
| Zou et al. | The facile synthesis of a Co 3 O 4–NiNP composite as an electrochemical non-enzymatic sensing platform for small chemical molecules | |
| Salandari-Jolge et al. | A copper oxide nanorod derived metal–organic framework nanocomposite: a robust and sensitive electrocatalyst for the detection of furazolidone | |
| CN110658249A (en) | Application of graphene-cerium dioxide composite material catalyst | |
| Sheng et al. | Synthesis of hollow Prussian blue cubes as an electrocatalyst for the reduction of hydrogen peroxide | |
| Zhang et al. | A ppb-level formaldehyde gas sensor based on rose-like nickel oxide nanoparticles prepared using electrodeposition process |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200107 |