Synthesis of Bimetallic Gold-Silver Nanoclusters and Its Application as Pb (II) Sensing Based on Fluorescence Technique

Abstract

Much research has been done on gold nanoclusters stabilized by biomolecules because of their remarkable fluorescence properties and potential biological applications. Here, we synthesize bimetallic gold-silver nanoclusters in a protein template using Galvanic Exchange (GE) Method. The samples were analyzed using UV-visible spectroscopy, a fluorolog (fluorescence spectrometer), and a lifetime kit using Time-Correlated Single-Photon Counting method. It is found that the bimetallic gold-silver nanoclusters emit bright red fluorescence with a long fluorescence lifetime in the range of microseconds. The bimetallic gold nanoclusters were used for Pb (II) detection using fluorescence technique. The fluorescence intensity of nanoclusters increased as the concentration of added Pb (II) increased. This work suggests that bimetallic gold-silver nanoclusters can be used for Pb detection with a detection limit of 15 nmol/L and this sensing will contribute to providing clean water without Pb contamination.