CN110146484A - One kind being based on Cu2The pesticide qualitative discrimination method of O/Ag SERS sensor - Google Patents

Abstract

The invention discloses one kind to be based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, belongs to the technical fields such as Food Monitoring.The different size of Cu with meso-hole structure is prepared by the concentration and additional amount that change ammonium hydroxide₂O mesoporous microsphere, with smallest size of Cu₂Based on O mesoporous microsphere, different amounts of AgNO is added in optimal conditions₃Solution is reducing agent in Cu by the ascorbic acid in mother liquor₂The attachment of O mesoporous microsphere surface generates Ag nano particle, finally constructs Cu₂O/Ag composite nano surface enhances Raman substrate, the Cu generated under different condition₂O/Ag degree of adhesion is different, obtains the optimal Cu of degree of adhesion by scanning electron microscope₂O/Ag composite nano surface enhances Raman substrate, which has been provided simultaneously with stronger adsorption capacity, can with enhance Raman signal after pesticide molecule Electrostatic Absorption, by screening raman characteristic peak, the discrimination model of different pesticides is established in conjunction with deterministic algorithm.This method is easy to operate, and detection speed is fast, precision is higher, stability is good, can be applied in the residual in-situ investigation of food middle peasant.

Description

One kind being based on Cu2The pesticide qualitative discrimination method of O/Ag SERS sensor

Technical field

Invention describes one kind to be based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, by Cu₂O is mesoporous micro- Ball and Ag combine to enhance the Raman signal of pesticide molecule, and set chemometrics method establishes the qualitative discrimination mould of pesticide Type.The method of the present invention is easy to operate, and detection speed is fast, precision is higher, stability is good etc. may be implemented high-volume original to pesticide Position detection.This method is suitable for the technical fields such as food safety, materials chemistry.

Background technique

The invention and use of pesticide undoubtedly substantially increase the yield of crops, but with a large amount of of pesticide and unreasonably It uses, the pesticide residue in food is negatively affected caused by human health also increasingly to be revealed.Development is quick, reliable, clever Quick and practical Analytical Techniques of Pesticide Residues, which is undoubtedly, to be controlled pesticide residue, guarantee eater's safety and avoids international related trade The basis of easy controversial issue.If excessive uses pesticide, due to its strong adsorption, residual minim medicament will cause certain harm, Application method is improper, then the toxic side effect that people can be caused different with livestock degree.Harmful pesticide residue not only with national people Body is closely related safely, and has become an important factor for influencing the trade of China's food import and export.Therefore, the residual detection of agriculture is important Becoming increasingly conspicuous for property, shows higher target to its analysis detection result.The residual limit standard of the agriculture that countries in the world reduce year by year With the detection project of cumulative year after year, higher requirement, conventional the Detection Technologies of Pesticide Residues are shown to its analyzing detecting method There are many defects in analyte detection process, especially in terms of sensitivity, accuracy, testing cost, detection.Cause This, studies efficient, accurate, the sensitive modern residue detection means of one kind and is of great significance.Conventional at present is used for agriculture The detection method of medicine Diacloden mainly has immuno analytical method, instrument analysis technology, spectral analysis technique.

Immuno analytical method is simple, sensitive, plays a significant role in farming residual analysis detection.Most common method has: enzyme Immunological technique, radioimmunoassay technique and golden immunological technique.Immunoenzyme techniques (Enzyme immunoassay, EIA) are mainly used Enzyme is marked, and connect after labeled with antigen (or antibody), makes antibody and enzyme-labelled antigen knot using the specific reaction of the two It closes (or antigen is combined with enzyme labelled antibody), reaction substrate is then added, carried out by the chromogenic reaction of enzyme and respective reaction object The qualitative and quantitative analysis of determinand.Radioimmunoassay technique (Radioimmunoassay, RIA) is that one kind combines high sensitivity Radioisotopic tracer and high degree of specificity antigen/precursor reactant, object letter is obtained by tracking to isotope The detection and analysis of breath.Golden immunological technique (Immune colloidalgold labeling technique, ICG) mainly utilizes The high density that gold particle has makes its existing stain under the junction of golden labelled protein only instrument amplification, and matches corresponding At body can naked eye regard powder (red) point, so can be used for qualitative and half-quantitative detection.Pesticide residue inspection based on immuno analytical method Survey method can reduce the use of poisonous and harmful reagent, keep detection operation succinct, reaction sensitivity with higher, but still There are some disadvantages, such as enzyme viability to be limited in scope, and causes the scope of application for detecting object limited, the use of antigen-antibody Higher cost etc..

Instrument analysis technology, it is main at present with using gas chromatography, high performance liquid chromatography, gas chromatography-mass spectrography and The detection of liquid chromatography-mass spectrometry progress pesticide residue.Gas chromatography (Gas Chromatography, GC) is mainly foundation The difference of the different target spot properties and its breadth coefficient of gas phase and stationary phase, makes Multiple Pesticides between gas and solid two-phase Repeatedly distribution, to realize the separation of target detection object, is finally sequentially separated.High performance liquid chromatography (High Performance Liquid Chromatography, HPLC) is to build on Traditional liquid phase chromatography, and merge gas phase The related mechanism and technology of chromatography, to detect and quantify a kind of modern separate analytical technique of heterogeneity ratio.Gas phase color Spectrum-mass spectrum (Gas Chromatography-Mass Spectrometry, GC-MS) is a kind of by gas chromatograph and mass spectrograph As a whole, wherein GC is used for the ingredient in separating mixture；The effect of MS is molecular weight, the molecule to unknown compound Formula or functional group are identified.Liquid chromatography-mass spectrometry (Liquid Chromatography-Mass Spectrometry, It LC-MS) is a kind of analysis method for using liquid chromatograph and mass spectrograph as a whole.Upper the method analysis ability By force, detection range is wide, and result has the features such as reliable and stable, high sensitivity and favorable reproducibility, and mature is formed centainly Professional standard, but its pre-treatment step is complicated and detection process is many and diverse, instrument and equipment is expensive, analysis time is very long, and specificity is not Obviously, and need professional operator's auxiliary that could complete analysis detection.Therefore, it is not suitable with the quick detection at scene, it is also unfavorable The purpose of Fast Determination of Pesticide Residue in popularization and application and realization milk.

In recent years, with the fast development of technical device, a series of spectrum analysis detection methods are come into being.It leads herein Domain, the Detection Technologies of Pesticide Residues being commonly used at present include: high light spectrum image-forming, fluorescence spectrum, FT-IR & FT-RAMAN spectra. Compared with traditional analyzing detecting method, spectroscopic analysis methods have the characteristics that quick, easy, environmental protection, can be used for pesticide residue Quick detection, provide some new solutions for the detection of Pesticide Residues.But meanwhile they there is also certain Deficiency, be still weak in terms of the precision of quantitative analysis and sensitivity.Such as hyperspectral technique and infrared spectrum technology try The spectrum statistical nature for having tested pesticide, is suitable for the Pesticides Testing of higher concentration, and for micro or trace pesticide residue Detection effect has much room for improvement；Light spectral technique deposits it equally in application range because some pesticides do not have fluorescent characteristic In certain limitation.

Surface enhanced Raman spectroscopy (Surface-Enhanced Raman Scattering, SERS) technology is Raman light The extension of spectrum with it is perfect.The finger print information of the available molecular structure of its spectrum has powerful molecule distinguishability, is molecule The promising approach of information quick obtaining.Therefore, quick, Sensitive Detection sensing of the surface-enhanced Raman method in building trace materials In terms of device, very big concern and application has been obtained.According to the Raman peak intensity under measured object specific wavelength, measured object can establish Linear relationship between concentration and Raman peak intensity realizes the quantitative analysis to measured object concentration.In the recent period, studies have shown that effectively Semiconductor material and noble metal nano particles are combined to the intensity that can effectively enhance SERS.By semiconductor material with it is expensive The obtained novel SERS substrate of metal composite not only can be improved substrate stability and expand the application range of SERS spectra, also The type of SERS substrate is enriched, this has great importance to the exploration of SERS mechanism.SERS substrate tool produced by the present invention Have Cu₂O mesoporous microsphere and Ag nanometers of progress are compound, have the substrate also while with stronger adsorption capacity relatively strong SERS effect, can be improved detection pesticide stability and sensitivity.

Summary of the invention

The object of the present invention is to provide one kind to be based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor is sensitive Degree is high, highly reliable, detection speed is fast, realizes the quick label-free detection of Diacloden pesticide.

To achieve the goals above, technical solution of the present invention includes: to combine Cu2O mesoporous microsphere and Ag to enhance It is fixed to establish pesticide molecule using the theoretical Raman spectrum of Density function theory pesticide molecule for the Raman signal of pesticide molecule Measure the standard curve of detection.This method is suitable for the technical fields such as food safety, environmental monitoring.

Above-mentioned one kind is based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, by semiconductor Cu₂O material and Precious metals ag progress is compound to prepare compound surface enhanced Raman substrate, in conjunction with Raman spectroscopy and Chemical Measurement side Method constructs the qualitative discrimination system to pesticide molecule.It comprises the following specific steps that:

1) optimize Cu₂The size of O mesoporous microsphere:

Optimization one: in 15-20 DEG C of temperature range, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polycyclic oxygen Ethane triblock copolymer (P123) is dissolved in 30-60mL deionized water, and continues to stir several hours (1-5h)；? It is put into the 0-1 M copper chloride solution of 0-6mL in 50mL beaker, the different amounts of 14M ammonia spirit of 0.1-1mL and 30- is then added The P123 solution of 60mL persistently stirs dozens of minutes (10-60min)；Then the 0.6M ascorbic acid solution for 0-25mL being added is held Continuous reaction dozens of minutes (0-60min), above-mentioned reaction process are maintained at 15-20 DEG C.Finally respectively obtain bright yellow precipitate, cyan Clear solution, bright yellow precipitate, bright yellow precipitate, bright orange precipitating, cyan clear solution, blue clear solution, wherein precipitating Object is Cu₂O mesoporous microsphere.

Or optimization two: at a temperature of 15-20 DEG C, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polycyclic oxygen Ethane triblock copolymer (P123) is dissolved in 30-60mL deionized water, and continues to stir several hours (1-5h)；? It is put into the 0.2M copper chloride solution of 0-6mL in 50mL beaker, 0-25mL not same amount concentrated ammonia solution and 30-60mL is then added P123 solution, persistently stir dozens of minutes (10-60min)；Then the 0.6 M ascorbic acid solution that 0-25mL is added continues instead Dozens of minutes (0-60min) is answered, above-mentioned reaction process is maintained at a temperature of 15-20 DEG C.It is micro- to finally obtain bright orange precipitating, cyan Turbid solution, bright yellow precipitate, bright yellow precipitate, bright yellow precipitate, cyan clear solution, blue clear solution, wherein precipitating Object is Cu₂O mesoporous microsphere.

Optimization three: at a temperature of 15-20 DEG C, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polyethylene oxide Triblock copolymer (P123) is dissolved in 30-60mL deionized water, and continues to stir several hours (1-5h)；It is burnt in 50mL It is put into the 0.2M acetic acid copper solution of 0-6mL in cup, the 14M ammonium hydroxide or dense ammonia of 0-1g sodium chloride and 0.30-3.0ml is then added The P123 solution of water and 30-60mL persistently stirs dozens of minutes (10-60min)；Then the 0.6M Vitamin C of 0-25mL is added Acid solution sustained response dozens of minutes (0-60min), above-mentioned reaction process are maintained at 15-20 DEG C.Finally obtain bright orange or The orange sediment of ash is Cu₂O mesoporous microsphere.

All yellow or orange precipitating are shown that optimal case is that 0.3ml concentrated ammonia liquor is added by scanning electron microscope.

2) Ag nano particle is in Cu₂The synthesis on O mesoporous microsphere surface: at room temperature, change temperature: 50 DEG C, 80 DEG C Under, take the Cu of above-mentioned addition 0-25mL concentrated ammonia liquor reaction₂The silver nitrate solution 1-30mL that 4mM is added in O mother liquor 30-60mL (is added Knots modification: 1ml, 3mL, 5mL, 8mL, 16mL, 24mL) obtain the Cu of different degree of adhesion₂O/Ag nano-complex, silver nitrate exist Ag nano particle can be reduced into mother liquor under the action of ascorbic acid.

By the Cu of different degree of adhesion₂O/Ag nano-complex show that optimal case is that 50 DEG C of degree are lower and adds by scanning electron microscope Enter the silver nitrate solution 5mL of 4mM.

3) acquisition of sample surfaces enhancing Raman spectrum SERS: a certain amount of Cu is weighed₂O/Ag nano-complex is respectively and not The pesticide solution with concentration mixes 5 hours, and under 780nm laser excitation, Portable Raman spectrometer carries out spectra collection, utilizes Chemometrics algorithm carries out qualitative model foundation.

Compared with prior art, the present invention has the advantages that

1) surface enhanced Raman substrate prepared by the present invention, semiconductor material and precious metal material are combined as surface Raman enhances substrate.

2) surface enhanced Raman substrate prepared by the present invention, Cu₂Cu in O/Ag composite Nano substance₂The part O has mesoporous Structure can generate stronger adsorption capacity, Cu to object to be measured₂Ag nm part in O/Ag composite Nano substance can have Stronger surface Raman enhancement effect.

3) present invention detects pesticide using non-marked method, saves testing cost, improves detection speed.

4) detection method prepared by the present invention can be used for the in situ detection of Pesticide Residues, and detection speed is fast, Detection range is wide, stability, high sensitivity, is widely applied in technical fields such as food safety, environmental monitorings.

Detailed description of the invention

Fig. 1 is Cu₂O and Cu₂The phenogram of O/Ag: (A) is Cu₂The SEM of O schemes；It (B) is Cu₂The TEM of O schemes；

Fig. 2 is Cu₂The SEM of O/Ag schemes；

Fig. 3 (A) is Cu₂The XRD diagram of O；It (B) is Cu₂The XRD diagram of O/Ag；

Fig. 4 is the principal component analysis result figure of three kinds of pesticides.

Specific embodiment

Embodiment 1 is in order to further verify inspection of the detection method prepared by the present invention to three kinds in food different pesticides Survey effect, present example, by taking Acetamiprid, Diacloden, rust go the detection of saliva pesticide as an example, specific steps are as follows:

1) optimize Cu₂The size of O mesoporous microsphere:

Optimization one: first that 0.612g polyethylene oxide-polypropylene oxide-polyethylene oxide three is embedding at a temperature of 18 DEG C Section copolymer (P123) is dissolved in 30mL deionized water, and continues to stir 3 hours；It is put into 3mL's in 50mL beaker Then the 14 M ammonia spirits of 0.35mL and the P123 solution of 30mL are added in 0.2 M copper chloride solution, persistently stir 30 minutes； Then it is added 0.6 M ascorbic acid solution sustained response 40 minutes of 5mL, above-mentioned reaction process is maintained at 16 DEG C.Only change and adds The amount for entering 14M ammonium hydroxide is tested according to above-mentioned steps, the variable are as follows: 0.15mL, 0.20mL, 0.25mL, 0.30mL, 0.40mL,0.45mL.Finally respectively obtain bright yellow precipitate, cyan clear solution, bright yellow precipitate, bright yellow precipitate, bright orange Color precipitating, cyan clear solution, blue clear solution, wherein sediment is Cu₂O mesoporous microsphere.

Optimization two: first that 0.612g polyethylene oxide-polypropylene oxide-polyethylene oxide three is embedding at a temperature of 18 DEG C Section copolymer (P123) is dissolved in 30mL deionized water, and continues to stir 3 hours；It is put into 3mL's in 50mL beaker Then the concentrated ammonia solution of 0.35mL and the P123 solution of 30mL is added in 0.2 M copper chloride solution, persistently stir 30 minutes；So It is added afterwards 0.6 M ascorbic acid solution sustained response 40 minutes of 5mL, above-mentioned reaction process is maintained at 16 DEG C.Only change and is added The amount of concentrated ammonia liquor is tested according to above-mentioned steps, the variable are as follows: 0.15mL, 0.20mL, 0.25mL, 0.30mL, 0.40mL, 0.45mL.Finally respectively obtain bright orange precipitating, the slightly cloudy solution of cyan, bright yellow precipitate, bright yellow precipitate, glassy yellow sink Shallow lake, cyan clear solution, blue clear solution, wherein sediment is Cu₂O mesoporous microsphere.

Optimization three: first that 0.612g polyethylene oxide-polypropylene oxide-polyethylene oxide three is embedding at a temperature of 18 DEG C Section copolymer (P123) is dissolved in 30mL deionized water, and continues to stir 3 hours；It is put into 3mL's in 50mL beaker Then the 14 M ammonium hydroxide or concentrated ammonia liquor and 30mL of 0.0093g sodium chloride and 0.30mL are added in 0.2 M acetic acid copper solution P123 solution persistently stirs 30 minutes；Then 0.6 M ascorbic acid solution sustained response 40 minutes of 5mL are added, above-mentioned reaction Process is maintained at 18 DEG C.Finally obtaining bright orange or grey orange sediment is Cu₂O mesoporous microsphere.

All yellow or orange precipitating are shown that optimal case is that addition 0.3mL is dense by scanning electron microscope and transmission electron microscope Ammonium hydroxide, particle size at this time are 200nm or so (Fig. 1), while can prove that the CuO of synthesis has from the XRD result of Fig. 3 A Preferable crystal form.

2) Ag nano particle is in Cu₂The synthesis on O mesoporous microsphere surface: at 25 DEG C, change temperature: at 50 DEG C, 80 DEG C, taking The Cu of above-mentioned addition 0.3mL concentrated ammonia liquor reaction₂The silver nitrate solution 1mL of 4mM is added in O mother liquor 30mL, only changes the nitre that 4mM is added The amount of sour silver solution is tested according to above-mentioned steps, the variable are as follows: 3mL, 5mL, 8mL, 16mL, 24mL are obtained different attached The Cu of degree₂O/Ag nano-complex, silver nitrate can be reduced into Ag nanometers in mother liquor under the action of ascorbic acid Grain.

By the Cu of different degree of adhesion₂O/Ag nano-complex show that optimal case is that 50 DEG C of degree are lower and adds by scanning electron microscope Enter the silver nitrate solution 5mL of 4mM, particle size is 400nm or so (Fig. 2) at this time, while can prove Cu from Fig. 3 B₂O/Ag's It synthesizes successfully.

3) acquisition of sample surfaces enhancing Raman spectrum SERS: a certain amount of Cu is weighed₂O/Ag nano-complex is respectively and not With pestsides synthesis 5 hours, under 780nm laser excitation, Portable Raman spectrometer carried out spectra collection, utilized Chemical Measurement Algorithm carries out qualitative model foundation.Fig. 4 is the principal component analysis result of three kinds of pesticides.

To sum up, the present invention relates to one kind to be based on Cu₂The quick Pesticides Testing method of O/Ag SERS sensor.This method are as follows: Cu2O mesoporous microsphere and Ag are combined to enhance the Raman signal of pesticide molecule, establishes different agricultures in conjunction with chemometrics method The chemometric model of medicine realizes its qualitative discrimination；This method is suitable for the technical fields such as food safety, environmental monitoring.

In the description of this specification, reference term " one embodiment ", " some embodiments ", " illustrative examples ", The description of " example ", " specific example " or " some examples " etc. means specific features described in conjunction with this embodiment or example, knot Structure, material or feature are included at least one embodiment or example of the invention.In the present specification, to above-mentioned term Schematic representation may not refer to the same embodiment or example.Moreover, specific features, structure, material or the spy of description Point can be combined in any suitable manner in any one or more of the embodiments or examples.

Although an embodiment of the present invention has been shown and described, it will be understood by those skilled in the art that: not A variety of change, modification, replacement and modification can be carried out to these embodiments in the case where being detached from the principle of the present invention and objective, this The range of invention is defined by the claims and their equivalents.

Claims (9)

1. one kind is based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, it is characterised in that: by semiconductor Cu₂O material With precious metals ag carry out it is compound prepare compound surface enhanced Raman substrate, in conjunction with Raman spectroscopy and Chemical Measurement side Method constructs the qualitative discrimination system to pesticide molecule.

2. according to claim 1 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In semiconductor Cu₂O material and precious metals ag carry out preparing Cu compared to common hydro-thermal method in compound preparation process₂O, this Invention slows down the hydrolysis of cuprous ion in reaction process using CuCl intermediate not soluble in water is first synthesized at a lower temperature Condensation rate ultimately forms the Cu with meso-hole structure₂O/Ag composite Nano substance.

3. according to claim 2 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In preparation Cu₂O/Ag composite Nano substance has effectively gathered the characteristic of semiconductor material and noble metal nano particles.

4. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O/Ag SERS sensor, feature exist In Cu₂Cu in O/Ag composite Nano substance₂The part O has meso-hole structure, can generate stronger adsorption capacity to object to be measured, Cu₂Ag nm part in O/Ag composite Nano substance can have stronger surface Raman enhancement effect.

5. according to claim 2 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In, further include, to be added ammonium hydroxide synthesize Cu₂The concentration of ammonium hydroxide and additional amount are optimized during O mesoporous microsphere, made Cu₂O mesoporous microsphere nano-scale is minimum, carries out to being added during silver nitrate synthesizes Ag nanometers to the additional amount of silver nitrate Optimization, make Ag nanometers in Cu₂The degree of adhesion on O mesoporous microsphere surface is optimal.

6. according to claim 1 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In using label-free method detection pesticide molecule.

7. according to claim 1 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In this method comprises the following specific steps that:

1) optimize Cu₂The size of O mesoporous microsphere:

Optimization one: in 15-20 DEG C of temperature range, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polyethylene oxide Triblock copolymer P123 is dissolved in 30-60mL deionized water, and continues to stir several hours；It is put into 50mL beaker Then the P123 solution of 0.1-1mL different amounts of 14M ammonia spirit and 30-60mL is added in the 0-1M copper chloride solution of 0-6mL, Persistently stir dozens of minutes；Then the 0.6M ascorbic acid solution sustained response dozens of minutes of 0-25mL is added, it is above-mentioned to react Journey is maintained at 15-20 DEG C.Finally respectively obtain bright yellow precipitate, cyan clear solution, bright yellow precipitate, bright yellow precipitate, bright Orange precipitating, cyan clear solution, blue clear solution, wherein sediment is Cu₂O mesoporous microsphere；Or optimization two: At a temperature of 15-20 DEG C, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123 It is dissolved in 30-60mL deionized water, and continues to stir several hours；The 0.2M chlorination of 0-6mL is put into 50mL beaker Then copper solution is added the P123 solution of 0-25mL not same amount concentrated ammonia solution and 30-60mL, persistently stirs dozens of minutes；So The 0.6M ascorbic acid solution sustained response dozens of minutes of 0-25mL is added afterwards, above-mentioned reaction process is maintained at 15-20 DEG C of temperature Under.Finally respectively obtain bright orange precipitating, the slightly cloudy solution of cyan, bright yellow precipitate, bright yellow precipitate, bright yellow precipitate, blueness Color clear solution, blue clear solution, wherein sediment is Cu₂O mesoporous microsphere；

Or optimization three: at a temperature of 15-20 DEG C, first by 0.5-2.0g polyethylene oxide-polypropylene oxide-polyethylene oxide Triblock copolymer P123 is dissolved in 30-60mL deionized water, and continues to stir several hours；It is put into 50mL beaker Then the 14M ammonium hydroxide or concentrated ammonia liquor and 30- of 0-1g sodium chloride and 0.30-3.0ml is added in the 0.2M acetic acid copper solution of 0-6mL The P123 solution of 60mL, persistently stirs dozens of minutes；Then the 0.6M ascorbic acid solution sustained response tens of 0-25mL is added Minute, above-mentioned reaction process is maintained at 15-20 DEG C.Finally obtaining bright orange or grey orange sediment is Cu₂O is mesoporous micro- Ball；

All yellow or orange precipitating are shown that optimal case is that 0.3mL concentrated ammonia liquor is added by scanning electron microscope；

2) Ag nano particle is in Cu₂The synthesis on O mesoporous microsphere surface: at room temperature, change temperature: at 50 DEG C, 80 DEG C, taking The Cu of above-mentioned addition 0-25mL concentrated ammonia liquor reaction₂The silver nitrate solution 1-30mL that 4mM is added in O mother liquor 30-60mL obtains different attached The Cu of degree₂O/Ag nano-complex, silver nitrate can be reduced into Ag nanometers in mother liquor under the action of ascorbic acid Grain；

3) acquisition of sample surfaces enhancing Raman spectrum SERS: a certain amount of Cu is weighed₂O/Ag nano-complex is respectively and various concentration The pesticide solution mix 5 hours, under 780nm laser excitation, Portable Raman spectrometer carry out spectra collection, utilize chemistry meter Amount learns algorithm and carries out qualitative model foundation.

8. according to claim 7 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In silver nitrate solution is added knots modification and is respectively as follows: 1ml, 3mL, 5mL, 8mL, 16mL, 24mL.

9. according to claim 7 a kind of based on Cu₂The pesticide qualitative discrimination method of O/Ag SERS sensor, feature exist In by the Cu of different degree of adhesion₂O/Ag nano-complex show that the lower silver nitrate that 4mM is added of 50 DEG C of degree is molten by scanning electron microscope Liquid 5mL.