We report simultaneous photoelectrocatalytic (PEC) glucose sensing and biohydrogen generation for the first time from the direct PEC oxidation of glucose at multifunctional and robust Cu2O-TiO2 photocatalysts. Striking improvement of 30% in overall H2 gas evolution (∼122 μmol h(-1) cm(-2)) by photoholes assisted glucose oxidation opens a new platform in solar-driven PEC biohydrogen generation.