One-step Green Synthetic Approach for the Preparation of Orange Light Emitting Copper Nanoclusters for Sensitive Detection of Mercury(II) Ions

Abstract

In this paper, we synthesized water-soluble fluorescent Cu nanoclusters (Cu NCs) through simple reduction reaction with 2-mercaptobenzimidazole as a protective agent, polyvinyl pyrrolidone (PVP) as a stabilizer and ascorbic acid as a reducing agent for the first time. The optical properties and structures of as-prepared Cu NCs were characterized by fluorescence spectroscopy, UV-vis, FT-IR, TEM and XPS. The characterization results showed that the Cu NCs had better fluorescence intensity, high dispersion and large Stokes shift. The Cu NCs had excellent stability against photo-illumination and ionic strength and displayed an excitation-independent fluorescence characteristic. The as-prepared Cu NCs was selectively and sensitively quenched by Hg2+. Furthermore, the fluorescence of Cu NCs was linearly quenched in the range of 2–40 μM (concentration of Hg2+) with a detection limit of 23.0 nM. More importantly, this prepared Cu NCs could be successfully utilized as a probe for detection of Hg2+ in real water samples.