Sandwich structure molecularly imprinted sers substrate and preparation method and application thereof

Abstract

The invention provides a sandwich structure molecularly imprinted SERS substrate, and a preparation method and application thereof. The preparation method comprises the following steps: polymerizing gold nanoparticles on the surface of graphene oxide by using p-aminothiophenol as an intermediate agent; and polymerizing an upper molecular imprinting layer on the compound by taking a biguanide hypoglycemic agent as a template molecule, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. The graphene oxide provides a good binding site for the molecularly imprinted polymer, the molecularly imprinted polymer has selective adsorption capacity, and the gold nanoparticles play a role in SERS enhancement. Compared with an existing detection technology, the preparation method has the following advantages: the sandwich structure molecularly imprinted SERS substrate MIP@Au-GO is obtained by adopting a mode of synthesizing polymers step by step, thesynthesis method is simple, the size, the number and the distance between the gold nanoparticles and target molecules are controllable, the adsorption efficiency is high, the detection effect is stable, and the application prospect is wide.

Description

technical field [0001] The invention belongs to the technical field of health product detection, and in particular relates to a molecularly imprinted SERS substrate with a sandwich structure and a preparation method and application thereof. Background technique [0002] Biguanide hypoglycemic drugs mainly include metformin hydrochloride and phenformin hydrochloride, which have the advantages of significant efficacy on diabetes and low price. The state expressly prohibits the addition of drugs in health products, but some unscrupulous businesses indiscriminately add biguanide hypoglycemic drugs and other drugs to health products in pursuit of their own interests, seriously endangering people's health. There are many reports on the analysis of the detection of biguanides, mainly including high-performance liquid chromatography (HPLC) or methods combined with other techniques, electrochemical sensing methods, and fluorescence spectroscopy. Although these methods have their own...

AI Technical Summary

Problems solved by technology

However, when SERS emphasizes the signal enhancement effect of the analyte, it ignores the poor selectivity of the analyte in SERS. When the analyte is a complex mixture or the concentration in the system is very low, the SERS measurement is susceptible to interference from impurities.

[0004] The existing Raman spectroscopy detection methods for hypoglycemic drugs in health products have the following disadvantages: (1) Most of them can only realize the detection of a single sample, and different detection methods need to be used for different targets; The characteristics of gold nanoparticles or silver nanoparticles are easy to be inactivated, and they often need to be prepared and used immediately, and the detection results are not stable, because the Raman detection intensity depends on the distance between the nanoparticles and the target molecule, and the added nanoparticles will randomly distribution, cannot be fixed

The above defects make Raman spectroscopy subject to certain limitations

Images