Highly luminescent near-infrared-emitting gold nanoclusters with further natural etching: photoluminescence and Hg2+ detection

Shuhong Lian,Dehong Hu,Pengfei Zhang,Changchun Zeng,Songhao Liu,Lintao Cai

doi:10.1186/1556-276x-7-348

Abstract

Highly luminescent near-infrared (NIR)-emitting gold nanoclusters (Au NCs) protected by glutathione with ultra-small size were prepared at high temperature following with a further natural etching at room temperature. The optical and surface properties of Au NCs were monitored by ultraviolet–visible and photoluminescence (PL) spectra, high-resolution transmission electron microscopy, and electrospray ionization mass spectrometry. The diameter of the etched Au NCs was reduced to approximately 1.35 nm with 30 % PL quantum yield. Interestingly, the PL of Au NCs was decreased obviously by the addition of Hg2+ and increased by the addition of Pb2+ at certain concentration. Our preliminary results illustrated that the highly luminescent NIR-emitting Au NCs would be an alternative probe for the detection of heavy metal ions in water and environmental monitoring.

Highlights

Gold nanoclusters (Au NCs) have received extensive attention because of their interesting optical properties [1,2,3], fluorescence [4,5], magnetism [6], and redox properties [7], as well as their potential applications in many fields such as optics [8,9,10] and catalysis [11,12]
We reported a novel synthetic method, based on the capability of a common commercially available thiol ligands, GSH, for the preparation of ultrasmall size highly luminescent Au NCs at high temperature following with a further natural etching at RT with NIR emission (λem max = 650 nm, quantum yield (QY) % 30 %)
The maximum PLQY of the asprepared etched Au NCs was 30 %, which was higher than PL bovine serum albumin (BSA)-Au NCs reported by Ying's group [14]

Summary

Introduction

Gold nanoclusters (Au NCs) have received extensive attention because of their interesting optical properties [1,2,3], fluorescence [4,5], magnetism [6], and redox properties [7], as well as their potential applications in many fields such as optics [8,9,10] and catalysis [11,12]. To synthesize these highly fluorescent Au NCs, several methods have been developed.

Objectives

Methods

Results

Conclusion