Nanozymes enhancing field-effect transistor nanosensor for in-situ monitoring intracellular hydrogen peroxide release

Abstract

Field-effect transistor (FET) nanodevices are widely recognized as highly sensitive sensors for continuous detection of bioactive molecules like hydrogen peroxide (H₂O₂). However, accurate and real-time monitoring of H₂O₂ poses challenges due to its instability and low concentration in organisms. To address these challenges, we construct an enhanced FET by one-step interfacing with nanozymes that possess natural enzyme-like catalytic properties and exceptional stability. Specifically, reduced graphene oxide (RGO) is drop-casted onto the fabricated FET channel, after which the nanozymes are assembled with RGO through π-π stacking interactions. The nanozyme-functionalized FET sensor is able to realize continuous H₂O₂ monitoring, featuring a broad linear detection range (1 pM–10 nM), an ultralow detection limit (0.5 pM), high selectivity, and rapid response. Moreover, the sensor enables real-time monitoring of intracellular H₂O₂ release from cells cultured within the FET channel, demonstrating significant potential for distinguishing between cancer cells and normal cells. In addition, the sensor successfully tracks the dynamic regulation of intracellular H₂O₂ efflux under drug stimulation. This platform combines high sensitivity with excellent biocompatibility, making it highly promising for applications in cell metabolism research, disease diagnosis, and drug efficacy evaluation and screening.