A highly sensitive photoelectrochemical biosensor for CEA analysis based on hollow NiS@NiO/TiO2 composite with typal p-n heterostructure

• Published in: Talanta (Oxford) Vol. 246; p. 123523
• Main Authors: Zheng, Delun, Yang, Jianying, Zheng, Zengyao, Peng, Mingxuan, Chen, Jiayang, Chen, Yaowen, Gao, Wenhua
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-08-2022
• Subjects: Carcinoembryonic antigen detection; Hollow NiS@NiO; p-n type heterostructure; Photoelectrochemical; p-n type heterostructure; Carcinoembryonic antigen detection; Hollow NiS@NiO; Photoelectrochemical
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123523

Heterostructured construction is regarded as a valuable approach to improve photoelectrochemical (PEC) performances. Herein, porous hollow NiS@NiO spheres were prepared derived from the Ni(TCY) MOFs precursor. Photoactive TiO2 was coupled with as-prepared NiS@NiO to form a close heterojunction interface of NiS@NiO/TiO2. NiS@NiO/TiO2 modified ITO electrode (NiS@NiO/TiO2/ITO) displayed fiercely enhanced photocurrent response, which was 4687-fold than that of NiS@NiO/ITO (0.008 μA) and 8.5-fold than that of TiO2/ITO (4.41 μA), respectively. Remarkable PEC property could be ascribed to the hollow NiS@NiO spheres with thin-shell structure provided there is a larger active surface area for harvesting the visible light. Most importantly, the p-n type NiS@NiO/TiO2 heterojunction could lead to generating more photo-excited charge carriers (e−/h+) and efficiently hinder the recombination of carriers, resulting in significantly augmented photocurrent output. Based on this outstanding PEC property, NiS@NiO/TiO2/ITO electrode fabricated sensing platform (BSA/anti-CEA/NiS@NiO/TiO2/ITO, BSA=Bovine serum albumin) exhibited high sensitivity for monitoring CEA (Carcinoembryonic antigen). Wide linear detection range was from 0.001 to 45 ng mL-1 and with a low detection limit of 1.67 × 10-4 ng mL-1 (S/N = 3). Prepared biosensors also showed good reproducibility, stability and had satisfying specificity. Thus, the proposed NiS@NiO/TiO2 heterostructured composite afforded well-design and synthesis strategy for constructing high-performance photoactive materials from MOFs-derivate.
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•The hollow NiO@NiS spheres could improve the visible-light absorption capacity.•The thin-wall NiO@NiS with large surface area provided abundant photoactive sites for surface-related reactions.•The p-n type NiO@NiS/TiO2 heterojunction dramatically improved the photo-to-electron conversion efficiency.•The close connected NiO@NiS/TiO2 with their synergistic photoelectric effect elevated photocurrent output.