CN114062336B - Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode - Google Patents
Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode Download PDFInfo
- Publication number
- CN114062336B CN114062336B CN202111395000.2A CN202111395000A CN114062336B CN 114062336 B CN114062336 B CN 114062336B CN 202111395000 A CN202111395000 A CN 202111395000A CN 114062336 B CN114062336 B CN 114062336B
- Authority
- CN
- China
- Prior art keywords
- nitrogen
- carbon quantum
- herbicide
- fluorescent carbon
- solution
- 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.)
- Active
Links
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 75
- 238000000034 method Methods 0.000 title claims abstract description 24
- 239000000575 pesticide Substances 0.000 title claims abstract description 18
- 241000196324 Embryophyta Species 0.000 title description 3
- 239000004009 herbicide Substances 0.000 claims abstract description 64
- 230000002363 herbicidal effect Effects 0.000 claims abstract description 61
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 32
- 239000011259 mixed solution Substances 0.000 claims description 28
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 21
- 229910052757 nitrogen Inorganic materials 0.000 claims description 16
- 239000000243 solution Substances 0.000 claims description 16
- 239000007864 aqueous solution Substances 0.000 claims description 14
- 230000005284 excitation Effects 0.000 claims description 14
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 12
- 229910021642 ultra pure water Inorganic materials 0.000 claims description 11
- 239000012498 ultrapure water Substances 0.000 claims description 11
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 9
- 235000012055 fruits and vegetables Nutrition 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 8
- 239000004809 Teflon Substances 0.000 claims description 6
- 229920006362 Teflon® Polymers 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 6
- 239000000843 powder Substances 0.000 claims description 6
- 239000012086 standard solution Substances 0.000 claims description 6
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 3
- 239000004202 carbamide Substances 0.000 claims description 3
- 238000000502 dialysis Methods 0.000 claims description 3
- 239000000706 filtrate Substances 0.000 claims description 3
- 238000004108 freeze drying Methods 0.000 claims description 3
- 239000012528 membrane Substances 0.000 claims description 3
- 238000001471 micro-filtration Methods 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 239000006228 supernatant Substances 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 239000012045 crude solution Substances 0.000 claims description 2
- 239000012535 impurity Substances 0.000 claims description 2
- 238000001308 synthesis method Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims 1
- 235000013399 edible fruits Nutrition 0.000 abstract description 5
- 235000013311 vegetables Nutrition 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 abstract description 3
- YZHUMGUJCQRKBT-UHFFFAOYSA-M sodium chlorate Chemical compound [Na+].[O-]Cl(=O)=O YZHUMGUJCQRKBT-UHFFFAOYSA-M 0.000 abstract description 3
- 238000003786 synthesis reaction Methods 0.000 abstract description 3
- 238000010791 quenching Methods 0.000 abstract description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 16
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 10
- 239000000523 sample Substances 0.000 description 9
- 150000002500 ions Chemical class 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000002452 interceptive effect Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- -1 K) + Chemical class 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 125000003277 amino group Chemical group 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000002189 fluorescence spectrum Methods 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 229910021389 graphene Inorganic materials 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000001027 hydrothermal synthesis Methods 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- KLSJWNVTNUYHDU-UHFFFAOYSA-N Amitrole Chemical compound NC1=NC=NN1 KLSJWNVTNUYHDU-UHFFFAOYSA-N 0.000 description 1
- 244000025254 Cannabis sativa Species 0.000 description 1
- 239000005946 Cypermethrin Substances 0.000 description 1
- 108010043121 Green Fluorescent Proteins Proteins 0.000 description 1
- 206010019695 Hepatic neoplasm Diseases 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- 239000005802 Mancozeb Substances 0.000 description 1
- 208000024770 Thyroid neoplasm Diseases 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- AAMATCKFMHVIDO-UHFFFAOYSA-N azane;1h-pyrrole Chemical compound N.C=1C=CNC=1 AAMATCKFMHVIDO-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000011258 core-shell material Substances 0.000 description 1
- KAATUXNTWXVJKI-UHFFFAOYSA-N cypermethrin Chemical compound CC1(C)C(C=C(Cl)Cl)C1C(=O)OC(C#N)C1=CC=CC(OC=2C=CC=CC=2)=C1 KAATUXNTWXVJKI-UHFFFAOYSA-N 0.000 description 1
- 229960005424 cypermethrin Drugs 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007850 fluorescent dye Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000010335 hydrothermal treatment Methods 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 208000014018 liver neoplasm Diseases 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 125000004433 nitrogen atom Chemical group N* 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000005424 photoluminescence Methods 0.000 description 1
- ATROHALUCMTWTB-OWBHPGMISA-N phoxim Chemical compound CCOP(=S)(OCC)O\N=C(\C#N)C1=CC=CC=C1 ATROHALUCMTWTB-OWBHPGMISA-N 0.000 description 1
- 229950001664 phoxim Drugs 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 238000006557 surface reaction Methods 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 210000001685 thyroid gland Anatomy 0.000 description 1
- 208000013076 thyroid tumor Diseases 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000002371 ultraviolet--visible spectrum Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6402—Atomic fluorescence; Laser induced fluorescence
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
- G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
- G01N2021/6432—Quenching
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/30—Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change
Landscapes
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Immunology (AREA)
- Analytical Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Pathology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
Abstract
The invention discloses a method for detecting pesticide weed killer based on a nitrogen-doped fluorescent carbon quantum dot fluorescence on-off-on mode, which is convenient for synthesis, has good and stable fluorescence characteristic, and comprises the following steps of 3+ Can quench the fluorescence, and the weed killer can be combined with Fe 3+ The specific combination enables quenched fluorescence to be recovered within 1-2 min, so that the method can rapidly and specifically detect the herbicide strength, and can be used for detecting the herbicide strength in fruits, vegetables and water samples.
Description
Technical Field
The invention belongs to the technical field of organic matter detection, and particularly relates to a method for detecting the herbicide controlling intensity of a pesticide by using a carbon quantum dot fluorescence on-off-on method.
Background
The herbicide is strong in herbicide, also called 3-amino-1, 2, 4-triazole, and is a non-selective chemical herbicide. Because of its very high solubility in water (280 g/L in water at 25 ℃), leaching may occur under certain conditions, such as in sandy soil with low organic carbon content and high water level, resulting in pollution of ground and surface water, and its relatively poor volatility (boiling point 245 ℃), which is characteristic that it tends to cause the concentration of the herbicide in the body of water, serious pollution of the body of water, and contamination of vegetable foods (fruits, vegetables) by water as a medium. Excessive exposure to grass may cause injury to the alveoli of humans and even thyroid and liver tumors, thus potentially damaging the environment and human health. Therefore, the establishment of the method for detecting the herbicide controlling strength of the pesticide with high selectivity, convenience and rapidness is significant.
Carbon quantum dots, which were discovered for the first time in 2004 as a novel nanomaterial, have attracted widespread attention because of their high chemical stability, good electrical conductivity and luminescence, and good biocompatibility. The carbon quantum dots are typically sp with a diameter of less than 10nm 2 /sp 3 /sp 2 -sp 3 The collection of hybridized carbonaceous entities has specific quantum confinement and edge effect. The carbon quantum dot hasSingle-layer or multi-layer graphene structures, and therefore typically have a graphene lattice, often with a large number of oxygen-containing functional groups on the surface, are now generally defined as a class of graphene structures having carbon (mainly sp 2 ) Core and surface passivated functional group core-shell nanomaterials. The application of various dopants and the research progress of the surface functionalization of the carbon quantum dots at present improve the fluorescence performance of the carbon quantum dots, improve the chemical stability of the carbon quantum dots and lead the carbon quantum dots to have wider application prospect.
Disclosure of Invention
The invention aims to provide a method for sensitively and rapidly detecting the herbicide controlling intensity of a pesticide by using a carbon quantum dot fluorescence on-off-on method.
The technical scheme adopted for solving the technical problems comprises the following steps:
1. nitrogen-doped fluorescent carbon quantum dot aqueous solution and Fe 3+ Sequentially adding the solution into a centrifuge tube, and then using ultrapure water to fix the volume to ensure that the concentration of the nitrogen-doped fluorescent carbon quantum dots in the obtained mixed solution A is 0.6-1.0 mug/mL and Fe 3+ The concentration of the mixture A is 0.015-0.030 mmol/L, and the fluorescence intensity F of the obtained mixture A at 430nm is recorded under the excitation wavelength of 340nm 0 。
2. Nitrogen-doped fluorescent carbon quantum dot aqueous solution and Fe 3+ Sequentially adding the solutions into a centrifuge tube, adding a standard solution of the herbicide strength, and then using ultrapure water to fix the volume to enable the nitrogen doped fluorescent carbon quantum dots and Fe in the obtained mixed solution B 3+ The concentration of the mixture is the same as that of the step 1, the mixed solution B is oscillated for 1 to 2min and then the fluorescence intensity F of the mixed solution B added with the standard solution of the herbicide strength with different concentrations at 430nm is recorded under the excitation wavelength of 340nm, and the fluorescence intensity F is recorded as F-F 0 And drawing a standard curve of the change of fluorescence intensity along with the concentration of the herbicide by taking the addition concentration of the herbicide as an ordinate and the addition concentration of the herbicide as an abscissa.
3. And (3) when the sample to be tested is tested according to the method of the step (2), the fluorescent intensity at 430nm under 340nm excitation wavelength is compared with the linear equation of the standard curve in the step (2), so that the concentration of the herbicide in the sample to be tested can be calculated.
The synthesis method of the nitrogen-doped fluorescent carbon quantum dot comprises the following steps: adding citric acid and urea into ultrapure water according to the mass ratio of 1:1, uniformly mixing, adding the mixture into a Teflon high-pressure reaction kettle, putting the Teflon high-pressure reaction kettle into a baking oven, keeping the temperature at 180 ℃ for 1h, naturally cooling to room temperature to obtain a nitrogen-doped fluorescent carbon quantum dot crude solution, adding a 1kw dialysis bag into the solution obtained by the reaction, dialyzing the solution into ultrapure water for 8-12 h to remove small molecular impurities, collecting the dialyzate, freeze-drying the dialyzate for 12-16 h to obtain blue nitrogen-doped fluorescent carbon quantum dot powder, and storing the blue nitrogen-doped fluorescent carbon quantum dot powder in a refrigerator at 4 ℃.
Fe of the above 3+ The solution is analytically pure FeCl 3 An aqueous solution.
The standard solution of the herbicide is aqueous solution of the herbicide.
The sample to be tested for the herbicide controlling intensity is fruits and vegetables or a water sample. When the sample to be tested is fruits and vegetables, the fruits and vegetables are added into a mixed solution of dichloromethane and acetic acid with the volume concentration of 1% in a volume ratio of 1:1 before detection, preferably, the addition amount of the fruits and vegetables in the mixed solution is controlled to be 20-30 g/100mL, the mixed solution is crushed, homogenized and centrifugally separated, a lower dichloromethane layer is removed, a supernatant is taken, and a 0.22 mu m microfiltration membrane is used for filtering, so that the obtained filtrate is used as the sample to be tested.
The beneficial effects of the invention are as follows:
the nitrogen-doped fluorescent carbon quantum dot is synthesized by a one-step hydrothermal method, is convenient to synthesize, has good fluorescent characteristic and water stability, and is Fe 3+ Can quench the fluorescence, and the weed killer can be combined with Fe 3+ The specific combination enables quenched fluorescence to be recovered within 1-2 min, so that the method can rapidly and specifically detect the herbicide strength and can be used for detecting the herbicide strength in fruits, vegetables and water samples.
Drawings
FIG. 1 is a graph of the ultraviolet visible absorption spectrum of nitrogen-doped fluorescent carbon quantum dots.
FIG. 2 is a graph of fluorescence spectra of nitrogen-doped fluorescent carbon quantum dots at different excitation wavelengths.
Fig. 3 is a transmission electron microscope and high resolution transmission electron microscope image of nitrogen doped fluorescent carbon quantum dots.
Fig. 4 is a particle size distribution diagram of nitrogen-doped fluorescent carbon quantum dots.
Fig. 5 is an X-ray diffraction pattern of nitrogen-doped fluorescent carbon quantum dots.
Fig. 6 is an X-ray photoelectron spectroscopy of a nitrogen-doped fluorescent carbon quantum dot.
Fig. 7 is a fourier infrared spectrum of a nitrogen-doped fluorescent carbon quantum dot.
FIG. 8 is a graph of Fe in the presence of various concentrations of herbicide 3+ Fluorescence spectrum diagram of mixed solution with nitrogen doped fluorescent carbon quantum dot.
FIG. 9 is Fe 3+ And a linear relation graph of the fluorescence intensity of the mixed solution of the fluorescent carbon quantum dots and the nitrogen doped fluorescent carbon quantum dots at 430nm along with the change of the concentration of the herbicide.
FIG. 10 is Fe 3+ The anti-interference performance of the mixed solution of the fluorescent carbon quantum dots and the nitrogen doped fluorescent carbon quantum dots on recognition of the herbicide strength.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, but the scope of the present invention is not limited to these examples.
Example 1
1. Adding 2g of citric acid and 2g of urea into 20mL of ultrapure water, uniformly mixing, adding into a Teflon high-pressure reaction kettle, putting the Teflon high-pressure reaction kettle into a baking oven, performing hydrothermal synthesis at 180 ℃ for 1h, dialyzing the obtained dark-loose green fluorescent carbon quantum dot solution with a 1kw dialysis bag for 12h, and freeze-drying to obtain blue nitrogen-doped fluorescent carbon quantum dot powder. As can be seen from fig. 1, the uv-vis absorption spectrum of the obtained nitrogen-doped fluorescent carbon quantum dot observes an absorption peak at 238nm, which is due to pi-pi transition of c=c bond of the oxidized aromatic structure, and the absorption band at 332nm is due to surface carboxyl group, amino group and other groups that passivate surface traps. When the excitation wavelength is changed from 310nm to 370nm, the fluorescence intensity of the nitrogen-doped fluorescent carbon quantum dot reaches a maximum value at 340nm and then further decreases, but the emission peak position is at 430nm and hardly changes with the change of the excitation wavelength (see fig. 2), and the characteristic of photoluminescence irrelevant to excitation is shown, which is the same as that of the reported carbon quantum dot. As can be seen from fig. 3, the obtained nitrogen-doped fluorescent carbon quantum dots are spherical particles with good dispersibility,the particle size ranges from 4nm to 13nm, the average particle size is 8nm (see fig. 4), and the high-resolution image shows that the high-resolution image has a lattice spacing of 0.32nm, which also proves the X-ray diffraction pattern (fig. 5) of the nitrogen-doped fluorescent carbon quantum dots. As shown in fig. 5, there are two peaks at 11.7 ° and 27.3 °, corresponding to lattice spacings of 0.75nm and 0.32nm, respectively, and the weaker peak at 2θ=11.7° is due to the lattice spacing with graphite oxide, indicating that the nitrogen-doped fluorescent carbon quantum dots are partially oxidized during synthesis; the sharp high intensity reflection at 2θ=27.3° is closer to the lattice spacing of graphene of 0.34nm, which suggests that the generated nitrogen-doped fluorescent carbon quantum dots have a graphene structure and demonstrates successful synthesis of the nitrogen-doped fluorescent carbon quantum dots. And analyzing the element composition and the chemical bond type in the synthesized nitrogen-doped fluorescent carbon quantum dots by adopting X-ray photoelectron spectroscopy. As shown in fig. 6, there are three major peaks at 284.6, 399.0 and 531.6eV corresponding to C1s, N1s and O1s, respectively, indicating successful incorporation of nitrogen atoms into the framework of carbon quantum dots by hydrothermal treatment. The doping concentration of nitrogen was found to be about 12.1% based on the peak intensities of carbon, nitrogen and oxygen. The high resolution spectrum of C1s exhibits three main peaks, with the strongest peak at 284.6eV corresponding to the sp of a carbon atom 2 The conjugated two-dimensional backbone structure, while the other two peaks at 288.19eV and 286.10eV are attributed to c=o bonds and C-O/C-N bonds. The high resolution spectrum of N1s shows that the nitrogen element hybridized mode is mainly represented by pyrrole nitrogen and graphite nitrogen. In addition, the nitrogen-doped carbon quantum dots were also characterized by Fourier infrared spectroscopy (see FIG. 7), which shows a spectrum of 3150cm -1 、1700cm -1 、1584cm -1 And 1399cm -1 There are 4 stronger peaks respectively representing the stretching vibration of-OH, the stretching vibration of C=O, the stretching vibration of N-H and the bending vibration of C-O-C, which indicates that a large number of amino groups, hydroxyl groups and carboxyl groups exist on the surface of the nitrogen-doped fluorescent carbon quantum dot, so that the nitrogen-doped carbon quantum dot has the potential of becoming a fluorescent probe with good hydrophilicity.
Adding the nitrogen-doped fluorescent carbon quantum dot powder into ultrapure water to prepare a 3 mug/mL nitrogen-doped fluorescent carbon quantum dot solution; mu.L of 3. Mu.g/mL fluorescent carbon quantum dot solution and 100. Mu.L of 0.1mmol/L were mixedFeCl 3 The aqueous solution was sequentially added to a 1.5mL centrifuge tube, the total volume was then adjusted to 400. Mu.L with ultrapure water, and the fluorescence intensity F at 430nm was recorded at an excitation wavelength of 340nm 0 。
2. Into a 1.5mL centrifuge tube, 100 mu L of 3 mu g/mL nitrogen-doped fluorescent carbon quantum dot solution and 100 mu L of 0.1mmol/L FeCl are added in sequence 3 The concentration of the aqueous solution and 200 mu L of the aqueous solution of the herbicide with the concentration of 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 80 and 100 mu g/mL respectively, the total volume is 400 mu L, the mixed solution is oscillated for 1min and then the mixed solution is added with the fluorescent intensity F of different concentrations of the herbicide at 430nm under the excitation wavelength of 340nm, and the fluorescent intensity F is recorded as F-F 0 And drawing a standard curve of the change of fluorescence intensity along with the concentration of the herbicide by taking the addition concentration of the herbicide as an ordinate and the addition concentration of the herbicide as an abscissa.
As can be seen from FIG. 8, fe with different concentrations of herbicide was added 3+ The fluorescence intensity of the mixed solution system of the fluorescent doped carbon quantum dots and nitrogen increases along with the increase of the concentration of the herbicide without red shift or blue shift, which proves that the herbicide can effectively recover Fe 3+ Fluorescence of the mixed solution system of the fluorescent carbon quantum dots doped with nitrogen. As can be seen from FIG. 9, the fluorescence intensity of the system is obviously changed along with the increase of the concentration of the herbicide in the system, which indicates that Fe 3+ The mixed solution system of the fluorescent carbon quantum dots has high detection sensitivity to the herbicide controlling intensity. Constructing a standard curve for detecting the herbicide strength, wherein when the concentration of the herbicide strength is 0-40 mug/mL, the difference value of the fluorescence intensity and the concentration of the herbicide strength are in a linear relation, the correlation coefficient is 0.9996, and the linear equation is as follows: y= 19.77318x-2.9781, where y is the difference in fluorescence intensity (F-F 0 ) X is the addition concentration of the herbicide. As can be seen from FIG. 9, F-F 0 Has good linear relation with the concentration of the herbicide. The lowest limit of detection was calculated using the formula for the lowest limit of detection (lod=3 s/K, s is the standard deviation of the blank, K is the slope of the linear equation) at 0.183 μg/mL (about 0.183 mg/kg), which is lower than the limit of 0.5mg/kg in fruits specified in the national standard.
3. Weighing 5g of fruit to be detected in a 50mL centrifuge tube, adding 10mL of dichloromethane and 10mL of acetic acid aqueous solution with volume concentration of 1%, crushing and homogenizing, centrifuging for 15min at a rotation speed of 5000r/min, discarding a dichloromethane layer at the lower layer, taking 5mL of supernatant, and filtering with a 0.22 mu m microfiltration membrane to obtain filtrate serving as a sample with the herbicide strength to be detected. And (3) when the sample to be tested is tested according to the method of the step (2), the fluorescent intensity at 430nm under 340nm excitation wavelength is compared with the linear equation of the standard curve in the step (2), so that the concentration of the herbicide in the sample to be tested can be calculated.
To prove the beneficial effects of the invention, fe is 3+ The mixed solution system of the fluorescent carbon quantum dots and the nitrogen doped fluorescent carbon quantum dots is used for testing the selectivity of the herbicide controlling intensity, and the test conditions are as follows:
into a 1.5mL centrifuge tube, 100 μL of 3 μg/mL nitrogen-doped fluorescent carbon quantum dot solution and 100 μL of 0.1mmol/L FeCl are sequentially added 3 Aqueous solution, 200. Mu.L of aqueous solution of strong herbicide at a concentration of 20. Mu.g/mL or 200. Mu.L of 1mmol/L interfering ions (e.g. K) + 、Na + 、Ca 2+ 、Mg 2+ 、Fe 2+ 、Cu 2+ 、SO 4 2- 、Cl - And HPO 4 2- The amount of interfering ions is 10 times of the amount of iron ions) or 200 mu L of 100 mu g/mL of other pesticides (such as mancozeb, phoxim and cypermethrin, the amount of the other pesticides is 5 times of that of the herbicide), the total volume is 400 mu L, the mixed solution is oscillated for 1min, and the fluorescence intensity of different interfering ions and pesticides added at 430nm is recorded under 340nm excitation wavelength.
As shown in FIG. 10, fe is present only in the presence of the herbicide 3+ The fluorescence intensity of the mixed solution system of the fluorescent carbon quantum dots doped with nitrogen is obviously recovered. All other pesticides and interfering ions do not react with Fe 3+ And reacting with a nitrogen-doped fluorescent carbon quantum dot mixed solution system. These results indicate that other ions and other pesticides have little interference with the fluorescence value of the system, indicating quenched Fe 3+ The mixed solution system of the fluorescent carbon quantum dots and the nitrogen has high selectivity for detecting the weed killing intensity of the target.
Claims (7)
1. A method for detecting the herbicide controlling intensity of a pesticide based on a nitrogen-doped fluorescent carbon quantum dot fluorescent on-off-on mode is characterized by comprising the following steps:
(1) Fluorescence of nitrogen dopingAqueous solution of photo-carbon quantum dots and Fe 3+ Sequentially adding the solution into a centrifuge tube, and then using ultrapure water to fix the volume to ensure that the concentration of the nitrogen-doped fluorescent carbon quantum dots in the obtained mixed solution A is 0.6-1.0 mug/mL and Fe 3+ The concentration of the mixture A is 0.015-0.030 mmol/L, and the fluorescence intensity F of the obtained mixture A at 430nm is recorded under the excitation wavelength of 340nm 0 ；
(2) Nitrogen-doped fluorescent carbon quantum dot aqueous solution and Fe 3+ Sequentially adding the solutions into a centrifuge tube, adding a standard solution of the herbicide strength, and then using ultrapure water to fix the volume to enable the nitrogen doped fluorescent carbon quantum dots and Fe in the obtained mixed solution B 3+ The concentration of the mixed solution B is the same as that of the step (1), after the mixed solution B is oscillated for 1-2 min, under the excitation wavelength of 340nm, the fluorescence intensity F of the mixed solution B added with the standard solution of the herbicide strength with different concentrations at 430nm is recorded, and the fluorescence intensity F is recorded as F-F 0 The addition concentration of the herbicide is the abscissa, and a standard curve of the change of the fluorescence intensity along with the concentration of the herbicide is drawn;
(3) And (3) testing the fluorescence intensity at 430nm under 340nm excitation wavelength when the to-be-tested herbicide controlling sample is added according to the method of the step (2), and calculating the concentration of the herbicide controlling sample in the to-be-tested herbicide controlling sample according to the linear equation of the standard curve of the step (2).
2. The method for detecting pesticide herbicide controlling intensity based on a fluorescent on-off-on mode of nitrogen-doped fluorescent carbon quantum dots according to claim 1, wherein the synthesis method of the nitrogen-doped fluorescent carbon quantum dots is characterized in that: adding citric acid and urea into ultrapure water according to the mass ratio of 1:1, uniformly mixing, adding the mixture into a Teflon high-pressure reaction kettle, putting the Teflon high-pressure reaction kettle into a baking oven, keeping the temperature at 180 ℃ for 1h, naturally cooling to room temperature to obtain a nitrogen-doped fluorescent carbon quantum dot crude solution, adding a 1kw dialysis bag into the solution obtained by the reaction, dialyzing the solution into ultrapure water for 8-12 h to remove small molecular impurities, collecting the dialyzate, freeze-drying the dialyzate for 12-16 h to obtain blue nitrogen-doped fluorescent carbon quantum dot powder, and storing the blue nitrogen-doped fluorescent carbon quantum dot powder in a refrigerator at 4 ℃.
3. The fluorescent on-off based on nitrogen-doped fluorescent carbon quantum dots according to claim 1-method for detecting the herbicide strength of a pesticide in an on mode, characterized in that: the Fe is 3+ The solution is analytically pure FeCl 3 An aqueous solution.
4. The method for detecting the herbicide controlling intensity of a pesticide based on a fluorescent on-off-on mode of nitrogen-doped fluorescent carbon quantum dots according to claim 1, wherein the method is characterized by: the standard solution of the herbicide is aqueous solution of the herbicide.
5. The method for detecting the herbicide controlling intensity of a pesticide based on a fluorescent on-off-on mode of nitrogen-doped fluorescent carbon quantum dots according to claim 1, wherein the method is characterized by: the sample to be tested for the herbicide controlling intensity is fruits and vegetables or a water sample.
6. The method for detecting the herbicide controlling intensity of a pesticide based on the fluorescent on-off-on mode of nitrogen-doped fluorescent carbon quantum dots according to claim 5, wherein the method is characterized in that: when the sample to be tested is fruits and vegetables, the fruits and vegetables are added into a mixed solution of dichloromethane and acetic acid with the volume concentration of 1% in a volume ratio of 1:1 before detection, the mixture is crushed, homogenized and centrifugally separated, a lower dichloromethane layer is removed, supernatant fluid is taken and filtered by a microfiltration membrane with the size of 0.22 mu m, and the obtained filtrate is used as the sample to be tested.
7. The method for detecting the herbicide controlling intensity of a pesticide based on the fluorescent on-off-on mode of nitrogen-doped fluorescent carbon quantum dots according to claim 6, wherein the method is characterized in that: adding fruits and vegetables into a mixed solution of dichloromethane and 1% acetic acid aqueous solution with volume ratio of 1:1, and controlling the adding amount of fruits and vegetables in the mixed solution to be 20-30 g/100mL.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111395000.2A CN114062336B (en) | 2021-11-23 | 2021-11-23 | Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111395000.2A CN114062336B (en) | 2021-11-23 | 2021-11-23 | Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114062336A CN114062336A (en) | 2022-02-18 |
| CN114062336B true CN114062336B (en) | 2023-06-30 |
Family
ID=80279565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111395000.2A Active CN114062336B (en) | 2021-11-23 | 2021-11-23 | Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114062336B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115494033A (en) * | 2022-07-06 | 2022-12-20 | 湖北中烟工业有限责任公司 | Method for detecting glyphosate |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103965504A (en) * | 2014-05-13 | 2014-08-06 | 江苏联合化工有限公司 | Preparation method of rear earth doped core-shell type fluorescent imprinting polymer |
| AU2020103861A4 (en) * | 2020-05-19 | 2021-02-18 | Sichuan Agricultural University | Preparation of chicken feather nitrogen-doped carbon quantum dots based fluorescent probes and paraquat detection method |
-
2021
- 2021-11-23 CN CN202111395000.2A patent/CN114062336B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103965504A (en) * | 2014-05-13 | 2014-08-06 | 江苏联合化工有限公司 | Preparation method of rear earth doped core-shell type fluorescent imprinting polymer |
| AU2020103861A4 (en) * | 2020-05-19 | 2021-02-18 | Sichuan Agricultural University | Preparation of chicken feather nitrogen-doped carbon quantum dots based fluorescent probes and paraquat detection method |
Non-Patent Citations (1)
| Title |
|---|
| 基于氮掺杂碳量子点荧光猝灭效应检测Fe~(3+);邓祥意;冯雅丽;李浩然;杜竹玮;滕青;康金星;王洪君;;分析化学(第10期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114062336A (en) | 2022-02-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110697681B (en) | Method for preparing carbon dots from broad beans, carbon dots and application thereof | |
| Radhakrishnan et al. | A green synthetic route for the surface-passivation of carbon dots as an effective multifunctional fluorescent sensor for the recognition and detection of toxic metal ions from aqueous solution | |
| Lai et al. | Hybrid carbon source for producing nitrogen-doped polymer nanodots: one-pot hydrothermal synthesis, fluorescence enhancement and highly selective detection of Fe (III) | |
| Tripathi et al. | Pollutant soot of diesel engine exhaust transformed to carbon dots for multicoloured imaging of E. coli and sensing cholesterol | |
| KR20160003231A (en) | Methods of producing graphene quantum dots from coal and coke | |
| CN108251108B (en) | Preparation of iron ion doped carbon quantum dot, obtained carbon quantum dot and application | |
| CN106573778A (en) | Bandgap engineering of carbon quantum dots | |
| CN114062336B (en) | Method for detecting pesticide weed control intensity based on nitrogen-doped carbon quantum dot fluorescence on-off-on mode | |
| CN108300462B (en) | Preparation of calcium ion doped carbon quantum dot, obtained carbon quantum dot and application | |
| KR101663748B1 (en) | Method of manufacturing nitrogen-doped carbon dots | |
| US10086334B2 (en) | Bandgap engineering of carbon quantum dots | |
| Shi et al. | Concentration-dependent multicolor fluorescent carbon dots for colorimetric and fluorescent bimodal detections of Fe 3+ and l-ascorbic acid | |
| CN106893585B (en) | Metal manganese doped carbon quantum dot with high fluorescence quantum yield and preparation method and application thereof | |
| CN114479113B (en) | Two-dimensional fluorescent MOFs composite material, preparation method and application thereof, and method for detecting iron ions through fluorescence | |
| CN113173575B (en) | Copper nanoparticle/fullerol nanocomposite material and preparation method and application thereof | |
| CN110327980A (en) | A kind of application of metal-doped carbon quantum dot | |
| CN109439321B (en) | Carbon quantum dot using silkworm excrement as raw material, preparation method and application thereof | |
| Xiang-Yi et al. | Synthesis of functionalized carbon quantum dots as fluorescent probes for detection of Cu2+ | |
| CN113214826A (en) | High-fluorescence quantum yield carbon quantum dot, preparation method thereof and application thereof in mercury ion detection | |
| KR102197222B1 (en) | Method of preparing carbon quantum dots using amino acid s and method for detecting lead | |
| CN109825293B (en) | Application of titanium carbide nanosheet as up-conversion material | |
| CN110257061A (en) | Method for preparing yellow fluorescence carbon dots using 2,3- diamino-pyridine and products thereof and application | |
| CN113527701B (en) | Tb-GMP/CeO2Composite material, preparation method thereof and method for detecting ziram | |
| Ghasemlou et al. | Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy | |
| Sawalha et al. | Carbon nanodots synthesized from used tobacco molasses as promising selective probes for Fe (III) ion sensing |
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 | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231117 Address after: 712100 C1, torch Park, free trade street, Yangling Demonstration Zone, Xi'an City, Shaanxi Province Patentee after: SHAANXI HEALTHFUL BIOLOGICAL ENGINEERING Co.,Ltd. Address before: 710062 No. 199 South Changan Road, Shaanxi, Xi'an Patentee before: Shaanxi Normal University |
|
| TR01 | Transfer of patent right |