Plasmonic Enhancement Coupling with Defect-Engineered TiO_2–<i>x</i>: A Mode for Sensitive Photoelectrochemical Biosensing

Abstract

This work demonstrates that the photoelectric response of defect-engineered TiO_2-x modified with Au nanoparticles can be modulated by oxygen vacancy concentration and excitation wavelength. When strongly plasmonic Au nanoparticles are anchored to defect-engineered TiO_2-x by DNA hybridization, several times plasmonic enhancement of photocurrent occurs under 585 nm excitation, and it is employed as a novel signaling mode for developing an improved photoelectrochemical sensing platform. This signaling mode combined with exonuclease III-assisted target recycling amplification exhibits excellent analytical performance, which provides a novel photoelectrochemical detection protocol.