Electron spin resonance and fluorescence imaging assisted electrochemical approach for accurate and comprehensive monitoring of cellular hydrogen peroxide dynamics

Abstract

Dynamic alteration in the levels of cellular hydrogen peroxide (H₂O₂) is closely related to a variety of human diseases, as well as signal transduction pathways that regulate cell survival and death. Although qualitative or quantitative methods are available for measuring either intra- or extra-cellular H₂O₂ levels, accurate and comprehensive in situ detection of the real-time H₂O₂ dynamics of living cells remains a significant challenge. To solve this problem, a novel multi-dimensional in situ cell assay platform combining electrochemistry, electron spin resonance (ESR) and optical imaging is designed. In this platform, the real-time concentration of extracellular H₂O₂ released from stimulated cells can be accurately detected by ESR assisted chronoamperometry, while the level of intracellular H₂O₂ is simultaneously monitored via the incorporated fluorescence imaging. Accurately and simultaneously analyzing the level variations of extra- and intra-cellular reactive oxygen species based on our assay platform can complement each other for further precise and in-depth investigation of their membrane transport and related cellular signaling, which will benefit disease diagnosis and treatment.