BSA-protected gold nanoclusters as fluorescent sensor for selective and sensitive detection of pyrophosphate

摘要

Gold nanoclusters (AuNCs) protected by bovine serum albumin (BSA) can emit red photoluminescence under illumination by ultraviolet light. The luminescence of the BSAa€“AuNCs was quenched when Cu2+ chelated with glycine in the BSA chain and generated BSAa€“AuNCsa€“Cu2+, while the luminescence of the BSAa€“AuNCs restored when pyrophosphate ion (P2O74a?’, PPi) was added and chelated with Cu2+, resulting in Cu2+ being removed from the surface of BSAa€“AuNCs. Bearing this in mind, herein we present a novel BSAa€“AuNCsa€“Cu2+ fluorescent sensor for PPi detection. This environmentally-friendly, simple, rapid and selective fluorescent sensor possesses a wide linear range (0.16a€“78.1 ??M) and a high sensitivity (the limit of detection (LD) is 0.083 ??M), which could also determine PPi in the effluent of copper plating with the results consistent with those obtained by absorptiometry. Furthermore, the morphologies of BSAa€“AuNCs, BSAa€“AuNCsa€“Cu2+ and BSAa€“AuNCsa€“Cu2+-PPi were characterized by high resolution transmission electron microscopy (HRTEM). The mechanism of the proposed assay for PPi detection has been discussed.