High‐Performance Triphase Bio‐Photoelectrochemical Assay System Based on Superhydrophobic Substrate‐Supported TiO₂ Nanowire Arrays

Abstract The design and fabrication of bio‐photoelectrodes that simultaneously possess rapid charge and gas‐phase mass transport abilities are highly desirable for the development of high‐performance bio‐photoelectrochemical assay systems. Here, a solid–liquid–air triphase bio‐photoelectrode is demonstrated by immobilizing glucose oxidase, a model redox active enzyme, onto 1D single crystalline TiO₂ nanowire arrays grown upon a superhydrophobic carbon textile substrate. Based on this triphase bio‐photoelectrode system, oxygen can be directly and constantly supplied from the air phase to sustain enzymatic reactions, leading to much enhanced oxidase kinetics. Further, the photogenerated electrons can transport rapidly and be efficiently collected along the nanowire arrays. The bio‐photoelectrochemical assay system demonstrates a significant wide detection range, high sensitivity, and selectivity as well as a low detection limit. The design principle is generally applicable to the fabrication of other triphase bio‐photoelectrodes, which offers an excellent opportunity for significant advances in environmental analysis and clinical diagnosis.