Aggregation-induced emission from gold nanoclusters for use as a luminescence-enhanced nanosensor to detect trace amounts of silver ions.

Several research have reported that silver ions (Ag(+)) could enhance the photoluminescence of some kinds of gold nanoclusters (AuNCs), and redox reaction involved mechanisms were recognized as the main reason to cause such phenomenon. However, in this work, we found that Ag(+) could enhance the luminescence of aggregation-induced emission gold nanoclusters (AIE-AuNCs) without valence state change. Upon addition of Ag(+), the luminescence of AIE-AuNCs enhanced instantly by 7.2 times with a red-shift of emission peak and a complete restoration of luminescence features was observed when Ag(+) was removed. A cost-effective, rapid-response, highly sensitive and selective method to detect trace amount of Ag(+) has thereby been established using AIE-AuNCs as a nanosensor. This analytical method exhibited a linear range of 0.5nM-20μM with a limit of detection of 0.2nM and it showed great promise for Ag(+) monitoring in environmental water.