Nanostructures for photoelectrochemical biosensing

Photoelectrochemical (PEC) biosensing has emerged as a highly promising analytical technique, leveraging the synergistic interplay of light and electrochemical processes to achieve sensitive, selective, and rapid detection of various molecules. The core of these advanced PEC biosensors lies in the strategic utilization of semiconductor nanostructures, which act as photoactive materials to convert light energy into measurable electrical signals. This review provides a comprehensive overview of recent advancements in semiconductor nanostructures for PEC biosensing, categorizing them based on their dimensional characteristics (0-D, 1-D, 2-D, and 3-D). Initially, the discovery, development and various applications of photoactive single nano-semiconductors in PEC biosensing are elucidated. Subsequently, the paper delves into sophisticated strategies employed to improve the photoelectric conversion efficiency and enhance the PEC biosensing performance. These strategies include surface modification with dyes, deposition of noble-metal nanoparticles, exploiting localized surface plasmon resonance, ion-doping, and the formation of intricate heterojunctions, such as type-II, Z-scheme, and S-scheme configurations, between multiple photoactive nanomaterials. Drawing upon recent literature, specific examples are provided to illustrate how these engineered nanostructures contribute to superior PEC performance, enabling the development of highly efficient biosensing platforms for diverse applications. Finally, the review concludes by highlighting current challenges and outlining future directions for the continued evolution of this dynamic field.