Fluorescence detection of glutathione reductase activity based on deoxyribonucleic acid-templated silver nanoclusters

•DNA-Ag nanocluster-based glutathione reductase sensor is reported for the first time.•It is based on fluorescence enhancement in the presence of glutathione reductase.•The present sensor exhibits good selectivity toward glutathione reductase.

Fluorescent silver nanoclusters stabilized by DNA (DNA-AgNCs) exhibit distinct response rates to thiol and disulfide. Glutathione reductase can catalyze the reduction of the oxidized glutathione (GSSG) quickly to reduced glutathione (GSH) in the presence of β-nicotinamide adenine dinucleotide 2′-phosphate reduced tetrasodium salt hydrate (NADPH). Consequently, DNA-AgNCs can serve as a new fluorescent platform for assaying the glutathione reductase (GR) activity. This newly proposed assay has a high sensitivity and a good selectivity toward GR. The GR activity can be detected in the range of 0.2–2.0 mU mL−1 with a minimum detectable concentration of 0.2 mU mL−1. Pepsin, lysozyme, trypsin, avidin, thrombin, myoglobin, and BSA have little effect on the fluorescence intensity of DNA-AgNCs. The GR activity assay is successfully used to monitor the inhibition of GR activity by a typical inhibitor 1,3-bis(2-chloroethyl)-1-nitrosourea.

Graphical abstractFluorescent silver nanoclusters stabilized by DNA have been used to develop a fluorescent platform for assaying glutathione reductase activity for the first time.Figure optionsDownload full-size imageDownload as PowerPoint slide