Na+ detection via brightening of synergistically originated noble metal nanoclusters

Abstract

Weakly fluorescent AuAg nanoclusters were obtained from glutathione, chloroauric acid, and silver nitrate aqueous solution under a modified hydrothermal method. Such glutathione-capped synergistically evolved clusters were obtained for the first time by employing our experimental conditions. Such weak fluorescence was made significantly brighter by employing Na⁺ and a Na⁺ sensor was obtained with a linear detection range of 10⁻⁵–5 × 10⁻⁹ M, while the limit of detection was 1.02 × 10⁻⁶ M. Na⁺ made the GSH matrix positively charged to stabilize AuAg clusters resulting in strong emissive properties. Furthermore, the effect of solvents, sunlight exposure, and temperature was gauged. Estimation of Na⁺ concentration was undertaken for natural water samples to demonstrate the practical utility of the designed nanosensor.