Analyzing volatile organic compounds in exhaled breath is a noninvasive method that has potential for disease assessment. Herein, acetone sensors based on porous In₂O₃flowers are synthesized through a Due to the ultrathin structure, functional groups and excellent physical-chemical properties, Two-dimensional (2D) MXenes shows great potential for biomedical applications. Here, we prepared TiO₂inverse opal photonic crystals (IOPCs)/Ti₃C₂quantum dots (QDs) composite film through the self-assembly method. Because of the widen absorption band of Ti₃C₂QDs, TiO₂IOPCs/Ti₃C₂composite film could have photocurrent effect from 280 to 900 nm, and the internal power conversion efficiency could reach to 26% at 350 nm. Owing to favourable energy levels, Ti₃C₂QDs were formed the Type-II Heterojunction with TiO₂, thus enabling directional transport charge for efficient charge separation. The Type-II Heterojunction photoelectrochemical (PEC) sensor consisting of TiO₂/Ti₃C₂/Nafion electrode exhibited high stability, sensitivity, and selectivity for the detection of glutathione in buffered solution and cell extracts. Thus, the TiO₂/Ti₃C₂/Nafion composite film provides a promising green electrode for sensitive PEC detection, which could realize some potential applications for disease early precaution and diagnose.