Molecularly Imprinted Au Nanoparticle Composites for Selective Sensing Applications

Abstract

In this study, a new method to imprint molecular recognition sites into Au nanoparticles (NPs) composites is described. The method includes the electropolymerization of thioaniline-functionalized Au NPs in the presence of imprint substrates that exhibit affinity interactions with the thioaniline-functionalized Au NPs or with a co-added ligand associated with the electropolymerizable NPs. Exclusion of the imprint substrate from the composite leads to the formation of selective imprinted sites in the Au NPs matrices. The imprinted matrices are implemented for the sensing of explosives, herbicides, saccharides, and ions. p-Donor–acceptor interactions, ionic interactions and H-bonds, or ligand–substrate interactions are used to generate the imprinted sites. The coupling between the localized plasmon of the NPs and the surface plasmon wave of the support is used to amplify the dielectric changes occurring in the NPs matrices upon the binding of the analytes to the imprinted sites, thus enabling the surface plasmon resonance (SPR) transduction of the sensing events. The imprinted Au NPs matrices demonstrate highly selective, stereoselective, and chiroselective sensing performance.