Plasmon-Induced Photopolymerization of Molecularly Imprinted Polymers for Nanosensor Applications

Abstract

A new simple, fast, and versatile method is developed to functionalize gold nanoparticles (AuNPs) via nanoscale layers of molecularly imprinted polymers (MIPs). The key step is based on near-field radical photopolymerization of the MIP prepolymerization mixture. This enables the fabrication of AuNPs@MIPs hybrid nanoparticles, which are used as substrates for localized surface plasmon resonance and surface-enhanced Raman spectroscopy (SERS) analysis with excellent sensitivity and specificity. To demonstrate the performance of AuNPs@MIPs, methylene blue-specific MIPs are prepared. The sensitivity of SERS detection is in the range of 10 nm. Specificity is demonstrated by comparing the response to a non-imprinted control polymer and by interference testing with two analogs (Rhodamine 6G and Rhodamine 110). This fabrication method allows to obtain robust and reusable sensor surfaces with high sensitivity and selectivity. The nanometric thickness of the MIP allows for shorter analysis times (10 min), thereby improving the performance of MIP-based sensors and opening up new perspectives for the detection of molecules at very low concentrations.