A label-free cytochrome c photoelectrochemical aptasensor based on CdS/CuInS2/Au/TiO2 nanotubes

• Published in: Sensors and actuators. B, Chemical Vol. 281; pp. 1088 - 1096
• Main Authors: Wang, Lijia, Gu, Wenhong, Sheng, Pengtao, Zhang, Zhiwei, Zhang, Bing, Cai, Qingyun
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.02.2019; Elsevier Science Ltd
• Subjects: Aptasensor; Cadmium sulfide; Cytochrome; Cytochrome c; Cytochromes; Electron transfer; Gold; Nanoparticles; Nanotubes; Photoelectric effect; Photoelectric emission; Photoelectrochemical; Quantum dots; TiO2; Titanium dioxide; Cytochrome c; Quantum dots; Aptasensor; Photoelectrochemical; TiO2
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.11.004

[Display omitted] •A photoelectrochemical aptasensor was proposed by using CuInS2 QDs sensitized TiO2 NTAs.•CdS/CuInS2/Au/TiO2 NTA photoelectrode was fabricated by deposition and dipping technique.•A cascade band gap structure was formed in the heterointerfaces of CdS QDs, CuInS2 QDs, and TiO2 NTAs.•The PEC aptasensor exhibited high sensitivity towards cyt c with a wide detection range between 5 pM to 100 nM. CdS/CuInS2/Au/TiO2 nanotube arrays (NTAs) were fabricated by deposition and dipping technique as well as successive ionic layer adsorption and reaction method, where Au nanoparticles were used to improve the interfacial electron transfer and quantum dots (QDs) of CdS and CuInS2 (4.1 nm) to stimulate the formation of an ideal stepwise band edge structure with TiO2. High and stable photocurrent responses were observed on the NTA electrode. A photoelectrochemical aptasensor toward cytochrome c (cyt c) was then fabricated by immobilization of HS-aptamer on the NTAs via Cd-S bond and Cu-S bond. Sensitive and selective detection of cyt c was achieved with a detection range of 5 pM to 100 nM.