서강대학교

초록 (요약문)

Hydrogen peroxide (H2O2) causes oxidative stress, which leads to harmful effects on the biological and environmental. For the detection of H2O2, many types of protein-stabilized gold nanoclusters (protein-AuNCs) have been developed. However, because of their low sensitivity, it is difficult to measure the low concentration of H2O2 in the marine environment. To overcome this limitation, our group develop enzyme-ball functionalized gold nanoclusters (EB-AuNCs) which are composed of bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs) and horseradish peroxidase-stabilized gold nanoclusters (HRP-AuNCs). The EB-AuNCs can sensitively detect H2O2 due to their two properties. The first is a continuous two-step fluorescence quenching mechanism. When the HRP-AuNCs react with the H2O2, the fluorescence of HRP-AuNCs is quenched and hydroxyl radical (•OH) is generated. After that, the fluorescence of BSA-AuNCs and HRP-AuNCs is quenched by the catalytic effect of •OH. Second, the proximity of two protein-AuNCs in a single EB-AuNCs allows •OH to fast reach adjacent protein-AuNCs so that the overall reaction rate improves and the loss of •OH in the solution decreases. Because of these properties, EB-AuNCs can detect up to 0.5 nM of H2O2 with good selectivity. Overall, the proposed sensing system provides highly sensitive detection tool.