In Situ Detection of Released H₂O₂ from Living Cells by Carbon Cloth-Supported Graphene/Au–Pt Nanoparticles

In this study, a 3D flexible sensing interface (CC/GWs/Au–Pt) with the direct growth of living cells was constructed for the rapid, sensitive, in situ, and real-time analysis and detection of hydrogen peroxide (H2O2). Similarly, graphene walls (GWs) vertically grew on the flexible and conductive carbon cloth (CC) by RF-PECVD, and Au–Pt nanoparticles were electrodeposited on CC/GWs to build an ultrasensitive sensing interface with good electrocatalytic activity. The proposed CC/GWs/Au–Pt platform shows good electrocatalytic performance for H2O2, and the detection limit was as low as 0.084 μM (84 nM) with wide linear range (1.5–98 and 148–7148 μM) and fast response (<5 s). In addition, the cells were able to adhere and grow well on the CC/GWs/Au–Pt sensing electrode, which was attributed to the good biocompatibility of CC/GWs/Au–Pt, providing a 3D microenvironment for the adhesion/growth of cells. Under the stimulation of drugs, this CC/GWs/Au–Pt biosensor achieved the real-time detection of released H2O2 by cells. The developed cell growth monitoring sensing interface can shorten the diffusion distance between reactive biomolecule and sensing interface, therefore improving the sensitivity and the accuracy of biosensor, which holds great promise for live-cell activity and its metabolites of continuous dynamic monitoring.