Culture and in situ H 2 O 2 -mediated electrochemical study of cancer cells using three-dimensional scaffold based on graphene foam coated with Fe 3 O 4 nanozyme

For real-time evaluation of the cell behavior and function under in vivo-like 3D environment, the 3D functionalized scaffolds simultaneously integrate the function of 3D cell culture, and electrochemical sensing is a convincing candidate. Herein, Fe 3 O 4 nanoparticles as the nanozyme (peroxide oxidase mimics) were modified on graphene foam scaffold to construct a 3D integrated platform. The platform displayed a wide linear range of 100 nM to 20 μM and a high sensitivity of 53.2 nA μM −1 toward detection of hydrogen peroxide (H 2 O 2 ) under the working potential of + 0.6 V (vs. Ag/AgCl). The obtained 3D scaffold also displayed satisfactory selectivity toward the possible interferents that appeared in the cell culture environment. Furthermore, the cells still maintained high cell viability (almost 100%) after their growth and proliferation on the scaffold for 7 days. With the superior performance on cell culture and electrochemical monitoring, the functions on the 3D culture of MCF-7 or HeLa cells and in situ monitoring of cell-released H 2 O 2 was easily achieved on this 3D platform, which show its great application prospects on further cancer-related disease diagnosis or drug screening. Graphical abstract A nanozyme-based three-dimensional graphene scaffold was successfully constructed for cell culture and identification of cancer cells through in situ electrochemical monitoring of the cell-released H 2 O 2 .