Selective determination of Ag⁺ in the presence of Cd²⁺, Hg²⁺ and Cu²⁺ based on their different interactions with gold nanoclusters

Abstract

A fluorescence method was developed for selective detection of Ag+ in the presence of Cd2+, Hg2+, and Cu2+ based on gold nanoclusters. The limit of detection for Ag+, Hg2+, Cd2+ and Cu2+ is 1.19 μM, 3.39 μM, 1.83 μM and 5.95 μM, respectively.

Bright Green Light-Emitting Gold Nanoclusters Confined in Insulin as Selective Fluorescent Switch Probes for Sensing and Imaging of Copper Ions and Glutathione

“…As shown in Figure S11, the intensity of almost all FTIR peaks of Ins/Au-NCs in the presence of Cu 2+ ions decreased, which can be attributed to the interaction of their insulin functional groups with these ions. Furthermore, Cu 2+ (d 9 ) as one of the paramagnetic ions facilitated the intersystem crossing (ISC) process, so it quenched the fluorescence of NCs due to passivation efficiency. , Hence, when combined with functional groups of amino acids of insulin, the paramagnetic behavior of the Cu 2+ cation caused Ins/Au-NCs to lose their energy due to ISC, and so, their fluorescence was quenched. On the other hand, the TEM images of Ins/Au-NCs solution in pH 8 PBS buffer showed an increase in size in the presence of Cu 2+ ions (Figure A).…”