Hydrogen Peroxide Quantitative Release And Its Interaction With Metalloproteins Secm-spr In Situ Study

Both hydrogen peroxide and hydroxyl radical are important compounds of the reactive oxygen species (ROS). They widely participate in the cell multiplication, differentiation and deterioration. The oxidation of biomolecules induced by H2O2 or OH·is responsible for the cell uncycled damage in the biology system. So, the research on the peroxidation of biomolecules induced by H2O2 or OH·using real-time and in-situ technique is critical to proclaiming and preventing oxidation stress of body. However, how to control the release of H2O2 or OH·is still a problem due to their high chemical activity (the average life time is just milli-second even to nano-second). In this article, the scanning electrochemical microscopy combined with surface plasmon resonance technique (SECM-SPR) was used to study the oxidation of Cu-metallothionein (Cu12+-MT) in the micro-space induced by quantitive released OH·, and the results indicated:(1) The SECM-SPR technique achieved the controllable release and the in-situ detection of H2O2. The quantitive release of H2O2 from the SECM tip was obtained through the reduction of oxygen. The micrometer distance between the tip and the substrate could eliminate the consumption of H2O2 via diffusion and side-reation, which ensured the 100% sequestration on the substrate. Compared with the off-line fluorenscence method, the production ratio of H2O2 detected by in-stiu release and sequestration using the SECM-SPR technique is higher, and the standard error of the detection was lower.(2) The real-time and in-situ sensitive detection of Cu12+-MT oxidation induced by OH·was realized using SECM-SPR technique. The release of H2O2 was controlled by the potential of the SECM tip. Produced OH·via interaction of released H2O2 with Cu12+-MT immobilized on the substrate, induced uncycled oxidation damage of Cu12+-MT, which could be monitored by SPR. The fluorenscence spectroscopy proved that OH·was produced during the interaction of H2O2 and Cu12+-MT. A good linear relation between the amount of released H2O2 and the oxidated Cu12+-MT was obtained.