Flexible and Stretchable Photoelectrochemical Sensing toward True-to-Life Monitoring of Hydrogen Peroxide Regulation in Endothelial Mechanotransduction

Hydrogen peroxide (H2O2) levels play a vital role in redox regulation and maintaining the physiological balance of living cells, especially in cell mechanotransduction. Despite the achievements on strain-induced cellular H2O2 monitoring, the applied voltage for H2O2 electrooxidation possibly gave rise to an abnormal expression and inadequate accuracy, which was still an inescapable concern. Hence, we decorated an interlaced CuO@TiO2 nanowires (NWs) semiconductor meshwork onto a polydimethylsiloxane film-supported gold nanotubes substrate (Au NTs/PDMS) to construct a flexible photoelectrochemical (PEC) sensing platform. Under white light irradiation, CuO@TiO2 NWs synergistically exhibited great stretchability and the PEC platform enabled stable photocurrent responses from the reduction of H2O2 even during mechanical deformation. Moreover, the admirable biocompatibility and an almost negligible open circuit voltage of +0.18 V for the CuO@TiO2 NWs/Au NTs/PDMS sensor guaranteed human umbilical vein endothelial cells (HUVECs) adhesion tightly thereon even under continuous illumination for 30 min. Finally, the as-proposed stretchable PEC sensor achieved sensitive and true-to-life monitoring of transient H2O2 release during HUVECs deformation, in which H2O2 release was positively correlated to mechanical strains. This investigation opens a new shade path on in situ cellular sensing and meanwhile greatly expands the application mode of the PEC approach.