NaBH4-Mediated Co-Reduction Synthesis of Glutathione Stabilized Gold/Silver Nanoclusters for Detection of Magnesium Ions

The content of magnesium ions (Mg2+) in drinking water is relatively high and the excessive Mg2+ingestion may lead to pathological lesions in the human body system. At present, the detection of Mg2+still relies on costly devices or/and complex organic fluorescence probes. To solve this problem, this work proposed a NaBH4-mediated co-reduction strategy for the synthesis of glutathione-stabilized bimetallic AuAg nanoclusters (GSH@AuAg NCs) with performance recognition to Mg2+. The preparation of GSH@AuAg NCs was simple and rapid and could be performed at mild conditions. The reaction parameters and sampling orders were optimized to understand the formation mechanism of GSH@AuAg NCs. The GSH@AuAg NCs exhibited a sensitive “light on” fluorescence response to Mg2+due to the re-molding of the interfacial physicochemical environment following the Mg2+coordination, which affected the surface charge transfer process, and thus led to a novel method for fluorescence detection of Mg2+with admirable selectivity for Mg2+. The proposed method showed a detection limit of 0.2 μM, and its practical utility for the detection of Mg2+in a real sample of purified drinking water was also demonstrated, confirming its practicability in monitoring the Mg2+concentration in drinking water.Keywords:bimetallic AuAg nanoclusters;coordination;glutathione;NaBH4;magnesium ions