MOF-derived porous carbon nanozyme-based flexible electrochemical sensing system for in situ and real-time monitoring of H2O2 released from cells

A novel flexible electrochemical sensor based on porous carbon nanosheets (PCNSs) nanozyme has been constructed for in situ and real-time monitoring of H2O2 released by cells. The PCNSs are prepared with the integration of thermal transformation, thermal activation and sonochemical exfoliation by using zeolitic imidazolate frameworks as template. The PCNSs exhibit high electrical conductivity, electrochemical activity and peroxidase-like catalytic properties, which is beneficial to H2O2 assay. With the transfer printing method, the flexible electrochemical sensor is obtained, which has excellent performances for H2O2 electrochemical detecting with wide linear range from 1 μM to 20 mM and a low detection limit of 0.76 μM. Owing to the great biocompatibility, the flexible sensor guarantees the growth of living cells for 72 h and realizes in situ and real-time monitoring the release of H2O2 from HeLa cells. The strategy of porous nanozyme preparation and flexible sensor construction provided a promising way for in situ and real-time assay of small molecules in the cellular microenvironment.