Ultrasensitive detection of silver(I) ions based on water-soluble micellized phosphorescent silver nanoclusters co-protected by 1,3-benzenedithiol and triphenylphosphine

Silver ion (Ag+) is one of the most toxic and dangerous heavy metal pollutants. Therefore, finding a simple, sensitive and selective approach to detect Ag+ is very urgent for environmental protection and risk reduction to human health. In this work, water-soluble red-emitting micellized phosphorescent silver nanoclusters (Ag-29 @Na micelles) with a large stokes shift of 380 nm are prepared and used as sensitive and selective phosphorescent probes to realize the rapid and simple detection of Ag+. Upon adding Ag+, the phosphorescence of Ag-29 @Na micelles is quenching, and the phosphorescence quenching ratio is linearly proportional to the Ag+ concentration over the range from 1 nM to 100 nM with the detection limit of 0.8 nM (S/N = 3). The Ag-29 @Na micelles exhibit high selectivity for Ag+ over other potentially interfering metal ions. The quenching mechanism of Ag-29 @Na micelles by Ag+ is studied in details using various analytical characterizations including UV-vis absorption spectroscopy, photoluminescence lifetime, X-ray photoelectron spectroscopy, transmission electron microscopy, and zeta potential, and the results denote that the aggregation between Ag-29 @Na micelles and Ag+ is responsible for the phosphorescence quenching. The Ag-29 @Na micelles-based phosphorescence probes are successfully applied to detect Ag+ in lake water samples with good recoveries of 98 %-108 %.

Automated summary

In this study, a simple, sensitive, and selective approach for detecting silver ions was developed using silver nanoclusters. The phosphorescence of the nanoclusters was quenched upon the addition of silver ions, and the quenching ratio was linearly proportional to the concentration of silver ions. The method exhibited high selectivity and was successfully applied to detect silver ions in lake water samples.