Utilization of in-situ self-supporting materials for the preparation of flexible and stretchable electrodes for the detection of nitric oxide released from cells

Real-time monitoring of nitric oxide from endogenously cells released is crucial for revealing their physiological activities or pathological processes. However, designing electrochemical sensors for real-time monitoring at the cellular level is challenging due to the simultaneous requirements of sensitivity, transient recording capability, and biocompatibility. Combining the universally self-supported grown highly active materials with stretchable conductive flexible substrates holds promise for achieving sensitive detection of cells and real-time monitoring of mechanically induced biomolecular release. However, existing manufacturing strategies for highly sensitive stretchable flexible electrochemical sensors still face significant challenges due to low material activity, high processing requirements, and the complexity of further designing membrane electrodes. Here, we designed a method of in-situ self-supported growth to grow Co-doped Ni(OH)2 structures on rigid Ti foil. Leveraging the synergistic effect of Co and Ni, sensitive detection of NO was achieved, enabling real-time monitoring of trace amounts of NO released by Raw 264.7 cells. Based on this material, using catalytic ink method, it was transferred to low-resistance flexible ITO film (LIF), enabling real-time monitoring of mechanically induced NO release from Human Umbilical Vein Endothelial Cells (HUVECs) cells. [Display omitted] •A simple in-situ synthesis Co-Ni(OH)2, enhancing NO detection (sensitivity: 8.0 μA μM–1 cm–2; LOD: 1.0 nmol L–1).•Spin-coating transferred rigid materials to flexible substrates (Co-Ni(OH)2/LIF) with high sensing (sensitivity: 5.2 μA μM–1 cm–2; LOD: 10.0 nmol L–1).•The Co-Ni(OH)2/Ti sensor shows excellent biocompatibility and catalytic performance for real-time NO tracking in living cells.•The Co-Ni(OH)2/LIF stretchable electrochemical sensor enables real-time and sensitive monitoring of NO release under cellular (HUVECs) mechanical induction.