1. Photoelectrochemical immunosensor for sensitive detection of alpha-fetoprotein based on a graphene honeycomb film.
- Author
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Wu, Yilun, Su, He, Yang, Junfeng, Wang, Zengyuan, Li, Daguang, Sun, Hang, Guo, Xingyuan, and Yin, Shengyan
- Subjects
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ALPHA fetoproteins , *HONEYCOMB structures , *GLUCOSE oxidase , *FLUORESCENT probes , *GRAPHENE oxide - Abstract
• A photoelectrochemical electrode was fabricated based on a graphene honeycomb film. • A fluorescent probe (AFP-PFBT-GOD) was synthesized for the detection current promotion. • This photoelectrochemical biosensor can sensitively detect alpha-fetoprotein by competitive immunoassay. • The photoelectrochemical biosensor has high detection sensitivity and good reliability. • The detection limit of alpha-fetoprotein is lower than 0.05 ng/mL. Alpha-fetoprotein (AFP) in adult serum often appears in early liver cancer. Therefore, early detection of an abnormal elevation of AFP concentration is important for the early diagnosis and treatment of primary liver cancer. In this work, a photoelectrochemical (PEC) electrode was fabricated for AFP-sensitive detection based on a reduced graphene oxide (rGO) honeycomb structure. After layer-by-layer bioconjugation, the immunoassay graphene electrode was modified with anti-AFP antibodies (Ab). Meanwhile, polymer nanoparticles (PFBT dots) were prepared via a nanoprecipitation method. In addition, the AFP was modified by using the PFBT dots and glucose oxidase (GOD), which formed a fluorescent probe (AFP-PFBT-GOD). By the competitive linkage of AFP and AFP-PFBT-GOD onto the anti-AFP modified honeycomb structure electrode, an immunosensor for AFP detection was obtained. During the PEC test, the electrons produced by the catalytic reaction of glucose and GOD can scavenge the photogenerated holes on the PFBT dots, which can reduce the recombination of photogenerated holes and electrons on the PFBT dots. The PEC immunosensor based on a rGO honeycomb structure exhibited a linear detection range of 0.05–100 ng/mL with a detection limit of 0.05 ng/mL. The excellent detection performance of the graphene PEC biosensor provides an opportunity for the early diagnosis of primary liver cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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