Plasmon-enhanced photoelectrochemical-SERS simultaneous dual-read-out determination of enrofloxacin based on bifunctional Bi2S3 quantum dots/triangular Ag nanoparticles/Ti3C2 MXene heterojunction

Abstract

The exploration of high-efficiency detection technologies of antibiotic residues plays vital roles for the evaluation of food quality and environmental safety risks owing to the adverse effects of antibiotics, which could accelerate the emergence of antibiotic-resistant genes. Herein, an integrated complementary dual-mode sensor was developed based on Bi2S3 quantum dots/triangular silver nanoparticles/Ti3C2 MXene (Bi2S3 QDs/T-Ag NPs/Ti3C2) heterojunction by in-situ coupling photoelectrochemical (PEC) analysis with surface-enhanced Raman spectroscopy (SERS) method. The bifunctional heterojunction could enhance light absorption, boost the generation of the electron-hole pairs, and facilitate the light-matter interactions, resulting in increased photoelectric conversion efficiency and enhanced Raman scattering for sensing applications. Moreover, the unique triangular shape and strong surface plasmon resonance effect of T-Ag NPs were conducted to further enhance the output signals of the dual-mode sensing platform. Such as-fabricated PEC/SERS detection system offered good complementarity and achieved mutually check via the combination of the inherent characteristics of two individual modes, which provided more accurate measurement results and more convincing information. Further, aptamer was adopted to recognize enrofloxacin molecules, which could achieve selective and sensitive detection of target. The detection limit of PEC and SERS was calculated as 0.61 fM (S/N = 3) and 0.21 fM (S/N = 3), respectively. Besides, the dual-mode aptasensor exhibited excellent stability and reproducibility, showing a promising prospect to detect enrofloxacin in real samples.