Surface-Imprinted Gold Nanoparticle-Based Surface-Enhanced Raman Scattering for Sensitive and Specific Detection of Patulin in Food Samples

As patulin is a kind of mycotoxin commonly found in fruit products, it is of great importance to develop simple and accurate analytical methods for the sensitive detection of patulin (PAT). In this work, based on molecular imprinted polymer (MIP) and surface-enhanced Raman scattering (SERS) technique, a specific and sensitive PAT sensor was developed. To prepare the MIP-SERS sensor, gold nanoparticles (Au NPs) were synthesized to act as supported substrate, 4-vinylpyridine (4-VP) served as functional monomer, 1,4-diacryloylpiperazine (PDA) served as cross-linker, PAT served as template molecule, and horseradish peroxidase (HRP) served as initiator. Owing to the good SERS character of Au NPs and excellent selectivity of MIP, the MIP-SERS sensor had a superior performance in PAT detection. Under the optimized conditions, this sensor exhibited a good linearity (R2 = 0.9877) with a range from 7.00 × 10−12 to 5.00 × 10−8 M for PAT. By simply incubating analytes with MIP-SERS substrate, the proposed method showed an enhanced SERS signal with a limit of detection of 5.37 × 10−12 M (S/N = 3). Besides, in the presence of interferences such as 2-oxindole (OXD) and 5-hydroxymethylfurfural (5-HMF), the MIP-SERS substrate showed good selectivity for PAT. What is more, the method had acceptable precision with recoveries of 96~108% in fruit product inspection, revealing its potential application in food analysis and safety verification.