Polyinosinic acid-stabilized fluorescent silver nanoclusters for sensitive detection of biological thiols

Water-soluble fluorescent Ag nanoclusters (NCs) were prepared with the assistance of commercially available polyinosinic acid (PI) as a template, which can be greatly quenched by trace biological thiols such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH). The developed PI-Ag NCs were used for highly sensitive and selective detection of the thiols with the linear ranges of 0.1-5 mu M (R-2 = 0.9962) for Cys, 0.5-4 mu M (R-2 = 0.9967) for Hcy, and 0.05-6 mu M (R-2 = 0.9958) for GSH, respectively. This method was extended for the detection of total thiols in human plasma samples with acceptable recovery from 95.21% to 101.60% and satisfactory relative standard deviations (<5%).