A label-free fluorescent probe for Hg2+ based on boron- and nitrogen-doped photoluminescent WS2

Abstract

The air-stable doping of transition-metal dichalcogenides is important in enabling a wide range of optoelectronic and electronic devices while exploring basic material properties. In this work, we develop for the first time a simple, low-cost synthesis route to preparing boron-and-nitrogen-doped WS₂ (B, N-WS₂) nanosheets. Bulk WS₂, a prototypical transition-metal chalcogenide material, is an indirect band-gap semiconductor with negligible photoluminescence. The obtained B, N-WS₂ nanosheets exhibited enhanced fluorescence. The B, N-WS₂ nanosheets can be used as a green and easy sensing platform for the label-free detection of Hg²⁺ because of the high sensitivity and selectivity toward Hg²⁺. Detection can also be easily accomplished through a rapid, one-step (within 1 min) operation, with a limit as low as 23 nM (S/N = 3).