Study Of Carbon Nanotube Substrate Based On SERS In The Detection Of Agricultural Residues

Pesticide residue is a more and more common phenomenon in agricultural production at present.As a big agricultural country,the pesticide consumption in China is large and the utilization range is wide,but the utilization rate is on the low side.Because of using pesticide untimely inappropriate and overdose for a long time,It brings a lot of pesticide residues,the rise of drug resistance of diseases and insect pests and environmental pollution.After the application of pesticides on different surfaces of fruits and vegetables,the distribution of pulp and pulp on the surface of fruits and vegetables is also different due to the different kinds and characteristics of pesticides.At present,the commonly used methods of solid-phase extraction and liquid chromatography chemical detection need to break the fruits and vegetables,enrich them by chemical means and then detect them.The operation is complex,and the instruments needed are bulky,which is not suitable for the requirements of on-site rapid and real-time detection.Raman spectrum detection has the characteristics of fast and non-destructive detection of pesticides.By using surface enhanced Raman method,we can better solve the problem of low pesticide residues and weak spectral signal on the surface of fruits and vegetables.In this paper,based on the study of surface enhanced Raman spectroscopy for the detection of diflubenzuron pesticides,silver particles with better enhancement effect are selected as the substrate,carbon nanotubes are used as the support of the substrate materials,and regular array and 3D structure are designed by using them.The Raman spectrum detection experiments of these two structures are carried out respectively,and the selected wave number range is 100-3200cm^-1,the concentration range of diflubenzuron is 5g/L-3mg/L,and the experimental data are displayed on the Origin software.By comparing the raman spectra of the substrates with different structures,the results showed that the carbon nanotubes with 3D structure had the best effect.By comparing the Raman spectra of different substrates,the 3D structure of carbon nanotubes is the best,and the enhancement factor was about 1.4*10⁵.According to the model established by the data,the decision coefficient is 0.998,the predicted RMS is 0.55mg/L.