A novel MOFs-functionalized microelectrode-based biosensor for real-time monitoring of hydrogen peroxide from tumor...

Sensitive real-time monitoring of hydrogen peroxide (H₂O₂) in the tumor microenvironment is crucial for comprehending its dual biological effects and enhancing therapeutic strategies. Existing techniques for real-time detection of H₂O₂ in tumor cells often suffer from limitations such as low sensitivity, poor selectivity, and difficult achievement of non-invasive dynamic monitoring. In this study, a high-performance electrochemical biosensor was developed based on metal-organic frameworks (MOFs) for non-invasive, real-time detection of H₂O₂ released by tumor cells. The sensor, featuring an integrated thin-film electrode constructed via microelectromechanical system (MEMS) technology, combined a biosensing interface film of AuNPs/ZIF-8@ZIF-67 and XC-72 carbon black with a poly(dimethylsiloxane) cell culture chamber, enabling real-time monitoring of H₂O₂ during cell culture. The sensor exhibited a wide linear detection range (1-350 μM), a low detection limit (0.908 μM), high stability (RSD = 4.57 %), and strong anti-interference (under 15 %). Compared to a system with discrete large-area electrodes, this integrated platform not only retained the detection performance but also effectively overcame the limitations associated with in situ cell culture.The system was successfully applied to monitor oxidative stress in various tumor cells under ascorbic acid stimulation. It effectively distinguished differences in H₂O₂ levels between tumor cells and normal cells, thereby underscoring its potential in tumor research and drug screening.This study provides an efficient and reliable platform for investigating tumor-related oxidative stress and assessing therapeutic responses.