Kinetic detection of hydrogen peroxide in single horseradish peroxidase-concentrated silica particle using confocal fluorescence microspectroscopic measurement

Talanta. 2024 Mar 16;273:125925. doi: 10.1016/j.talanta.2024.125925. Online ahead of print.ABSTRACTIn the present study, we propose a scheme for detecting H2O2 by using horseradish peroxidase (HRP) adsorbed onto single silica particles and fluorescence microspectroscopy. When the silica particles were immersed in an HRP solution, the HRP concentration in the silica particles increased by a factor of 690 compared to that in the bulk aqueous solution because HRP was adsorbed on the silica surface. When a single particle containing HRP was added to a mixed solution of H2O2 and Amplex Red, fluorescence from resorufin, which was produced by the reaction of HRP, H2O2, and Amplex Red, was observed. The fluorescence from the resorufin in the particles increased after a single particle was added to the solution, and the release of resorufin was observed. As the concentration of H2O2 (CH2O2) decreased, the time it takes for fluorescence intensity to reach its maximum was shorter. The detection limit for H2O2 in the present system was 980 nM. The reaction behavior of a single silica particle was evaluated using a spherical diffusion model, which explains the approximate concentration change of resorufin in the silica particle. The proposed method has the advantages of simple sample preparation and detection, low sample consumption, and a short detection time.PMID:38527412 | DOI:10.1016/j.talanta.2024.125925

Source: Talanta - March 25, 2024 Category: Chemistry Authors: Akihisa Miyagawa Kiyoharu Nakatani Source Type: research