Tailoring Heterojunction Interfaces for Enhanced Photoelectrochemical Biosensing

Photoelectrochemical (PEC) biosensors based on heterojunctions are widely used in bioanalysis for their rapid response and high sensitivity. However, their performance is often limited by inherent interfacial issues, such as poor contact and bandgap mismatch, which constrain the optimization of photoelectric properties and ultimate sensitivity. To address these challenges, recent research has focused on engineering both solid-solid and solid-liquid interfaces. Strategies like enhancing interfacial contact, constructing electron bridges, and promoting surface reactions have proven effective in facilitating carrier separation, migration, and utilization. This review classifies heterojunctions and systematically analyzes how interface design governs carrier behavior and amplifies sensing signals. It further details their applications in biomolecular detection and concludes with future perspectives, highlighting the pivotal role of advanced heterojunction design in propelling PEC sensing technology forward.