Dual-drive strategy-based modulation of the interfacial charge of S-scheme heterojunction and photoelectrochemical ultrasensitive detection of CD44

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-10, Vol.417, p.136056, Article 136056
• Main Authors: Li, Yamei, Kuang, Xuan, Li, Faying, Ma, Hongmin, Wu, Dan, Jia, Hongying, Wu, Tingting, Ju, Huangxian, Wei, Qin
• Format: Article
• Language: English
• Subjects: Dual-drive strategy; PEC biosensor; S-scheme heterojunction; Sulfur vacancies; Thermal energy
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2024.136056

The efficacy of charge carrier separation plays a crucial role in influencing the practical application of photoelectrochemical (PEC) detection platforms, which can be meticulously engineered to realize highly sensitive detection at the sensing interface. Hence, a novel dual-drive strategy was proposed to integrate thermally-assisted external drive behavior with the internal drive behavior of sulfur vacancies (SVs), realizing the rapid separation of charge at the S-scheme heterojunction sensing interface. On the one hand, unabsorbed solar energy was utilized an external driving force to facilitate efficient photothermoelectric conversion within the In2S3/CdS heterojunction, achieving the photocurrent response intensity 1.5 times higher than conventional PEC detection methods. On the other hand, introducing sulfur vacancies (SVs) as internal driving forces induced ordered migration and directional flow of charge carriers. Moreover, density functional theory (DFT) calculations and experimental results demonstrated that photo-generated carriers achieved rapid separation along the S-scheme heterojunction. Under the optimal conditions, a biosensor constructed based on the dual-drive strategy exhibited high sensitivity for the CD44 (cluster of differentiation-44) cluster, with a low detection limit of 0.132 pg mL−1and a wide linear range of 0.001 ∼ 1000 ng mL−1. The proposed strategy offers new insights into how to effectively harness excess energy in the traditional ultraviolet spectral range for ultrasensitive biosensors. •Thermal energy external drive achieves efficient photothermoelectric conversion.•Sulfur vacancies drive directional charge migration internally.•Electron transfer pathway of S-scheme heterojunction is proved by first-principles.•The dual-drive strategy achieves ultrasensitive detection of CD44.