Bovine serum albumin stabilized silver nanoclusters as “signal-on” fluorescent probe for detection of hydrogen peroxide and glucose

A “signal-on” fluorescence method for determination of hydrogen peroxide (H 2 O 2 ) and glucose was developed using bovine serum albumin-capped Ag nanoclusters with thirty atoms (BSA-Ag 30 NCs) as sensing probe. It was relied upon the size-dependent fluorescence of BSA-AgNCs. The prepared BSA-Ag 30 NCs have an average diameter of ~3.4 nm and exhibit a red emission at 635 nm. The fluorescence intensity of BSA-AgNCs could be enhanced by H 2 O 2 with the etching and then formation of smaller nanoclusters. Under the optimum experimental conditions, a linear calibration curve for H 2 O 2 was obtained within the concentration range of 2–200 μM with detection limit of 1.1 μM. Coupling with glucose oxidase (GOD) catalytic reaction, the BSA-Ag 30 NCs sensing platform could also be used to detect glucose. The enhancement of fluorescence intensity (F–F 0 )/F 0 was linear related to the concentration of glucose over the range 5–180 μM with detection limit of 3.4 μM. This method was successfully applied to the determination of glucose in human serum samples with satisfactory result.