CN108732157A - One kind being based on Cu2The quick Pesticides Testing method of O@Ag SERS sensors - Google Patents

Abstract

The invention discloses one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, belongs to the technical fields such as Food Monitoring.First by generating the Cu with meso-hole structure based on the CuCl intermediates not soluble in water of generation₂Then silver nitrate solution is added in above-mentioned reaction mother liquor in O mesoporous microspheres, by the ascorbic acid in mother liquor be reducing agent in Cu₂The attachment of O mesoporous microspheres surface generates Ag nano particles, finally builds Cu₂O@Ag composite nano surfaces enhance 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, establish the standard curve of pesticide molecule detection.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 quick Pesticides Testing method of O@Ag SERS sensors

Technical field

Invention describes one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, by Cu₂O is mesoporous micro- Ball and Ag are combined to enhance the Raman signal of pesticide molecule, using the theoretical Raman light of Density function theory pesticide molecule Spectrum, establishes the standard curve that pesticide molecule quantitatively detects.The method of the present invention is easy to operate, and detection speed is fast, precision is higher, stablizes Property the high-volume in situ detection that may be implemented to pesticide such as good.This method is suitable for the technical fields such as food security, materials chemistry.

Background technology

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, ensure 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 can 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 have become influence China's food import and export trade an important factor for.Therefore, the residual detection of agriculture is important Becoming increasingly conspicuous for property, analyzes it testing result and shows higher target.The residual limit standard of 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 sensitivity, accuracy, testing cost, detection time limit etc..Cause This, a kind of efficient, accurate, sensitive modern residue detection means of research are 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 an important roll 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 is connect with antigen (or antibody) after labeled, 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 combining high sensitivity Radioisotopic tracer and high degree of specificity antigen/precursor reactant, pass through and object letter obtained to the tracking of 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 only instrument amplification of the junction of golden labelled protein, and matches corresponding At body can bore hole 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, have higher reaction sensitivity, 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 Cost is higher etc..

Instrument analysis technology, it is main at present with using gas chromatography, high performance liquid chromatography, gas chromatography-mass spectrography and Liquid chromatography-mass spectrometry carries out the detection of pesticide residue.Gas chromatography (Gas Chromatography, GC) is mainly foundation Gas phase and the different target spot properties of stationary phase and its difference of breadth coefficient, make Multiple Pesticides between gas and solid two-phase Repeatedly distribution, to realize the separation of target detection object, finally sequentially into ranks, separation.High performance liquid chromatography Method (High Performance Liquid Chromatography, HPLC) is to build on Traditional liquid phase chromatography, and merge gas The related mechanism and technology of phase chromatography, to detect and quantify a kind of modern separate analytical technique of heterogeneity ratio.Gas phase Chromatography-mass spectroscopy (Gas Chromatography-Mass Spectrometry, GC-MS) is a kind of by gas chromatograph and mass spectrum As a whole, wherein GC is used for the ingredient in separating mixture to instrument；MS's act as the molecular weight to unknown compound, divides Minor or functional group are identified.Liquid chromatography-mass spectrometry (Liquid Chromatography-Mass Spectrometry, LC-MS) it is a kind of analysis method 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 complicated, 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 result has much room for improvement；Light spectral technique makes it equally be deposited 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.Its spectrum can obtain the finger print information of molecular structure, have powerful molecule distinguishability, be molecule The promising approach of information quick obtaining.Therefore, quick, Sensitive Detection sensing of the surface-enhanced Raman method in structure trace materials In terms of device, prodigious concern and application have been obtained.According to the Raman peak intensity under measured object specific wavelength, measured object can be established 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 Semi-conducting material and noble metal nano particles are combined to the intensity that can effectively enhance SERS.By semi-conducting material with it is expensive The obtained novel SERS substrates of metal composite can not only improve substrate stability and expand the application range of SERS spectra, also The type of SERS substrates is enriched, this has great importance to the exploration of SERS mechanism.SERS substrates tool produced by the present invention Have Cu₂O mesoporous microspheres and Ag nanometers of progress are compound, make the substrate while with stronger adsorption capacity also with relatively strong SERS effects, can improve detection pesticide stability and sensitivity.

Invention content

The object of the present invention is to provide one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors 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 scheme of the present invention includes：Cu2O mesoporous microspheres and Ag are combined 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 security, environmental monitoring.

Above-mentioned one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, includes the following steps：

By semiconductor Cu₂O materials and precious metals ag carry out it is compound prepare compound surface enhanced Raman substrate, in conjunction with drawing Graceful spectral technique builds the quantitative detection architecture to pesticide molecule.Specifically include following steps：

Step 1) Cu₂The preparation of O mesoporous microspheres：At a certain temperature, first that polyethylene oxide-polypropylene oxide-is poly- Ethylene oxide triblock copolymer P123 is dissolved in deionized water, and continues to stir；Copper chloride solution is first added, then again Ammonia spirit and P123 solution is added, it is lasting to stir, generate CuCl intermediates；It is eventually adding ascorbic acid solution sustained response, Above-mentioned reaction process temperature remains unchanged, and the sediment for finally obtaining glassy yellow is Cu₂O mesoporous microspheres；

Step 2) Ag nano particles are in Cu₂The synthesis on O mesoporous microspheres surface：By the Cu of above-mentioned reaction₂O mother liquors are equally divided into 3 Part, to be added silver nitrate synthesize Ag nanometers during the addition of silver nitrate is optimized, make Ag nanometers in Cu₂O The degree of adhesion on mesoporous microsphere surface is optimal；

Step 3) sample surfaces enhance the acquisition of Raman spectrum SERS：The Raman of pesticide is detected using label-free method Characteristic peak, and the theoretical raman spectra calculated with density functional theory is compared, and the ownership of Characteristic Raman spectral peak is realized, To further establish the standard curve between Raman signal intensity and corresponding pesticide concentration.

Further, the detailed process of the step 1) is Cu₂The preparation of O mesoporous microspheres：At a temperature of 18 DEG C, first will 0.612g polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer P123s are dissolved in 30mL deionized waters, and And persistently stir 3 hours；It is put into the 0.2M copper chloride solutions of 3mL in 50mL beakers, the 14M ammonium hydroxide of 0.4mL is then added The P123 solution of solution and 30mL persistently stirs 30 minutes, generates CuCl intermediates；Then the 0.6M ascorbic acid of 5mL is added Solution sustained response 40 minutes, above-mentioned reaction process is maintained at 18 DEG C, and the sediment for finally obtaining glassy yellow is Cu₂O is mesoporous Microballoon.

Further, in the step 1), slowed down using CuCl intermediates not soluble in water are first synthesized at a lower temperature The hydrolytic condensation rate of cuprous ion, ultimately forms the Cu with meso-hole structure in reaction process₂O@Ag composite Nano substances.

Further, Cu is prepared₂O@Ag nano-complexes have effectively gathered semi-conducting material and noble metal nano particles Characteristic.

Further, Cu₂Cu in O@Ag composite Nano substances₂The parts O have meso-hole structure, are generated to object to be measured stronger Adsorption capacity, Cu₂Ag nm parts in O@Ag composite Nano substances have stronger surface Raman enhancement effect.

Further, in the step 2), silver nitrate solution 1mL, 4mL and 8mL that 4mM is added in difference obtain different attachments The Cu of degree₂O Ag nano-complexes, silver nitrate can be reduced into Ag nano particles in mother liquor under the action of ascorbic acid.

Further, in the step 3), a certain amount of Cu is weighed₂O@Ag nano-complexes are molten with the pesticide of various concentration respectively Liquid mixes 5 hours, and under 780nm laser excitations, Raman spectrum is acquired using the Portable Raman spectrometer voluntarily built, to Obtain the Raman spectrum of the pesticide.

Further, further include that pesticide molecule is detected using label-free method in the step 3), it is next with aptamers are connect The detection method for generating specific reaction compares.

Compared with prior art, the advantage of the invention is that：

1) surface enhanced Raman substrate prepared by the present invention, semi-conducting 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 substances₂The parts O have mesoporous Structure can generate stronger adsorption capacity, Cu to object to be measured₂Ag nm parts in O@Ag composite Nano substances can have Stronger surface Raman enhancement effect.

3) present invention detects Diacloden 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, in the technical fields extensive use such as food security, environmental monitoring.

Description of the drawings

Fig. 1 is Cu₂The phenogram of O@Ag composite Nano substances：(A) it is Cu₂O mesoporous microsphere scanning electron microscope characterizes；(B) it is Cu₂O@Ag scanning electron microscope characterizes；(C) it is Cu₂The X-ray diffractogram of O@Ag.

Fig. 2 is Cu made from different silver nitrate additive amounts₂O@Ag scanning electron microscope characterizes；(A) it is 1ml；(B) it is 4ml；(C) For 8ml；

Fig. 3 is the Surface enhanced Raman spectroscopy figure of various concentration Diacloden pesticide.

Fig. 4 is the canonical plotting (establishing standard curve respectively with three Raman shifts) of various concentration Diacloden pesticide； (A) it is Raman shift 1362cm^-1；(B) it is 1461cm^-1；(C) it is 1528cm^-1。

Specific implementation mode

Embodiment 1 is in order to further verify detection of the detection method prepared by the present invention to Diacloden pesticide in food Effect, present example, by taking the detection of Diacloden pesticide as an example, concrete operation step is as follows：

1)Cu₂The preparation of O mesoporous microspheres：At a temperature of 18 DEG C, first by 0.612g polyethylene oxide-polypropylene oxide- Polyethylene oxide triblock copolymer (P123) is dissolved in 30mL deionized waters, and continues to stir 3 hours；It is burnt in 50mL It is put into the 0.2M copper chloride solutions of 3mL in cup, the P123 solution of the 14M ammonia spirits and 30mL of 0.4mL is then added, continues Stirring 30 minutes；Then the 0.6M ascorbic acid solutions sustained response of 5mL is added 40 minutes, above-mentioned reaction process is maintained at 18 ℃.The sediment for finally obtaining glassy yellow is Cu₂O mesoporous microspheres.

2) Ag nano particles are in Cu₂The synthesis on O mesoporous microspheres surface：By the Cu of above-mentioned reaction₂O mother liquors are equally divided into 3 Point, the silver nitrate solution 1mL, 4mL and 8mL that 4mM is added in difference obtain the Cu of different degree of adhesion₂O@Ag nano-complexes, Silver nitrate can be reduced into Ag nano particles in mother liquor under the action of ascorbic acid.

3) acquisition of sample surfaces enhancing Raman spectrum SERS：Weigh a certain amount of Cu₂O@Ag nano-complexes are respectively and not Diacloden with concentration mixes 5 hours, under 780nm laser excitations, is acquired using the Portable Raman spectrometer voluntarily built Raman spectrum, with 1528cm^-1For the raman scattering intensity at place, to establish the mark between Raman signal intensity and corresponding Diacloden concentration Directrix curve.Fig. 1 is the phenogram of Cu2O@Ag composite Nano substances：(A) it is that Cu2O mesoporous microsphere scanning electron microscope characterizes；(B) it is Cu2O@Ag scanning electron microscope characterizes；(C) X-ray diffractogram for being Cu2O@Ag.Fig. 2 is made from different silver nitrate additive amounts Cu2O@Ag scanning electron microscope phenogram 3 is the Surface enhanced Raman spectroscopy figure of various concentration Diacloden pesticide.Fig. 4 is various concentration The canonical plotting (establishing standard curve respectively with three Raman shifts) of Diacloden pesticide.

To sum up, the present invention relates to one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors.This method is： Cu2O mesoporous microspheres and Ag are combined to enhance the Raman signal of pesticide molecule, using Density function theory pesticide molecule Theoretical Raman spectrum, establish the standard curve that pesticide molecule quantitatively detects；This method is suitable for food security, environmental monitoring etc. Technical field.

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 In the case of being detached from the principle of the present invention and objective a variety of change, modification, replacement and modification can be carried out to these embodiments, this The range of invention is limited by claim and its equivalent.

Claims (9)

1. one kind being based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, it is characterised in that：By semiconductor Cu₂O materials With precious metals ag carry out it is compound prepare compound surface enhanced Raman substrate, in conjunction with Raman spectroscopy, structure is to pesticide point The quantitative detection architecture of son.

2. according to claim 1 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In：Specifically include following steps：

Step 1) Cu₂The preparation of O mesoporous microspheres：At a certain temperature, first by polyethylene oxide-polypropylene oxide-polycyclic oxygen second Alkane triblock copolymer P123 is dissolved in deionized water, and continues to stir；Copper chloride solution is first added, then adds ammonia Aqueous solution and P123 solution, it is lasting to stir, generate CuCl intermediates；It is eventually adding ascorbic acid solution sustained response, it is above-mentioned anti- Process temperature is answered to remain unchanged, the sediment for finally obtaining glassy yellow is Cu₂O mesoporous microspheres；

Step 2) Ag nano particles are in Cu₂The synthesis on O mesoporous microspheres surface：By the Cu of above-mentioned reaction₂O mother liquors are equally divided into 3 Point, to be added silver nitrate synthesize Ag nanometers during the addition of silver nitrate is optimized, make Ag nanometers in Cu₂O is situated between The degree of adhesion of hole microsphere surface is optimal；

Step 3) sample surfaces enhance the acquisition of Raman spectrum SERS：The Raman signatures of pesticide are detected using label-free method Peak, and the theoretical raman spectra calculated with density functional theory is compared, and the ownership of Characteristic Raman spectral peak is realized, to Further establish the standard curve between Raman signal intensity and corresponding pesticide concentration.

3. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In the detailed process of the step 1) is Cu₂The preparation of O mesoporous microspheres：At a temperature of 18 DEG C, first by 0.612g polycyclic oxygen Ethane-polypropylene oxide-polyethylene oxide triblock copolymer P123 is dissolved in 30mL deionized waters, and continues stirring 3 A hour；It is put into the 0.2M copper chloride solutions of 3mL in 50mL beakers, the 14M ammonia spirits and 30mL of 0.4mL is then added P123 solution, persistently stir 30 minutes, generate CuCl intermediates；Then the 0.6M ascorbic acid solutions that 5mL is added continue instead It answers 40 minutes, above-mentioned reaction process is maintained at 18 DEG C, and the sediment for finally obtaining glassy yellow is Cu₂O mesoporous microspheres.

4. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In：In the step 1), slow down the reaction process Central Asia using CuCl intermediates not soluble in water are first synthesized at a lower temperature The hydrolytic condensation rate of copper ion, ultimately forms the Cu with meso-hole structure₂O@Ag composite Nano substances.

5. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In preparation Cu₂O@Ag nano-complexes have effectively gathered the characteristic of semi-conducting material and noble metal nano particles.

6. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In Cu₂Cu in O@Ag composite Nano substances₂The parts O have meso-hole structure, and stronger adsorption capacity is generated to object to be measured, Cu₂Ag nm parts in O@Ag composite Nano substances have stronger surface Raman enhancement effect.

7. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In in the step 2), silver nitrate solution 1mL, 4mL and 8mL that 4mM is added in difference obtain the Cu of different degree of adhesion₂O@ Ag nano-complexes, silver nitrate can be reduced into Ag nano particles in mother liquor under the action of ascorbic acid.

8. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In in the step 3), weighing a certain amount of Cu₂O@Ag nano-complexes mix 5 hours with the pesticide solution of various concentration respectively, Under 780nm laser excitations, Raman spectrum is acquired using the Portable Raman spectrometer voluntarily built, to obtain the pesticide Raman spectrum.

9. according to claim 2 a kind of based on Cu₂The quick Pesticides Testing method of O@Ag SERS sensors, feature exist In further including generating specificity instead with aptamers connects using label-free method detection pesticide molecule in the step 3) The detection method answered compares.