Facile preparation of bimetallic Au-Cu nanoclusters as fluorescent nanoprobes for sensitive detection of Cr3+ and S2O82- ions

Metallic nanoclusters (NCs) have attracted special attention from researchers due to their interesting optical properties. In this experiment, we proposed a facile one-step method for the synthesis of bimetallic gold-copper nanoclusters (AuCuNCs). The prepared AuCuNCs were characterized by fluorescence spectroscopy (FL), UV–vis absorption spectrum, transmission electron microscopy (TEM), etc. The emission peak of the prepared AuCuNCs was located at 455 nm and showed blue luminescence under the excitation of 365 nm UV light. Furthermore, after the addition of Cr3+ and S2O82- ions, the FL emission intensity of AuCuNCs was significantly reduced at 455 nm and there was a color change of diminished blue luminescence under UV lamp. The AuCuNCs exhibited excellent linearity and sensitivity for the detection of Cr3+ and S2O82- ions. The limits of detection (LOD) for the Cr3+ and S2O82- ions were calculated to be 1.5 and 0.037 μM, respectively. Finally, the recoveries of Cr3+ and S2O82- ions in Runxi Lake and tap water were measured by standard addition recovery test and were 96.66 ∼ 116.29 %, 95.75 ∼ 119.4 %.