A single-atom vanadium-doped 2D semiconductor platform for attomolar-level molecular sensing

Abstract

Semiconducting materials offer promising opportunities as ideal platforms for localized surface plasmon resonance (LSPR)-free surface-enhanced Raman spectroscopy (SERS)-based molecular detection. However, conventional semiconductor-based SERS substrates have various drawbacks that hinder their practical SERS application, including their low sensitivity, uniformity, reproducibility, and operational stability, and poor universal detection capability for diverse analytes. Herein, we present a facile and effective strategy for boosting various aspects of the SERS functionalities of a 2D semiconductor, 1T′ ReSe₂, to develop a practical LSPR-free SERS platform. Upon single-atom vanadium doping, the 1T′ ReSe₂ substrate exhibited strong coupling interaction and efficient photoinduced charge transfer resonance with probe molecules, leading to ultrahigh sensitivity with an attomolar detection limit. Moreover, the method employed for preparing the vanadium-doped ReSe₂ SERS substrate, viz., liquid precursor-assisted chemical vapor deposition-based synthesis with substitutional doping, endowed it with outstanding uniformity and reproducibility. Moreover, the as-prepared substrate demonstrated excellent operational stability and universal detection capability owing to its side catalytic effect-free feature, unique electronic structure, and strong interaction with analytes.