Highly sensitive molecular imprinted voltammetric sensor for resveratrol assay in wine via polyaniline/gold nanoparticles signal enhancement and polyacrylamide recognition

A highly sensitive molecular imprinted-based electrochemical sensor for resveratrol is described. Electrodeposition and electropolymerization techniques were successively used to prepare gold nanoparticles (AuNPs) and polyaniline (PANI) film on glassy carbon electrode. The as-formed porous PANI/AuNPs composite acted as a conducting network mediating electron transfer, and offered supporting matrix for anchoring the imprinted elements—polyacrylamide (PAM) that was chemically polymerized at the composite interface using acrylamide as functional monomer and resveratrol as template molecule in an amiable condition, thereby forming a molecular imprinted polymer (MIP) capable of specifically recognizing and electrochemically responding to resveratrol. The preparation conditions were carefully investigated aiming to obtain a high-performance MIP-based sensor for electrochemical sensing of resveratrol. Quantification was performed by differential pulse voltammetry in pH 4.0 phosphate buffer. The peak current was directly proportional to resveratrol concentration ranging from 1.0 μM to 200 μM, with detection limit of 87 nM. A variety of commonly coexisting ingredients such as ferulic acid, catechin, caffeic acid, vanillin, and protocatechin acid cannot produce detectable current signal in the given analytical condition, enabling the direct detection of resveratrol in wines without the requirement of sample pretreatment (e.g., chromatographic separation or solvent extraction).