A membraneless self-powered photoelectrochemical biosensor based on Bi2S3/BiPO4 heterojunction photoanode coupling with redox cycling signal amplification strategy
2022
Cao, Jun-Tao | Lv, Jing-Lu | Liao, Xiao-Jing | Ma, Shu-Hui | Liu, Yan-Ming
The photoelectrochemical (PEC) self-powered system has attracted great attention in disease detection. The determination of a simple and efficient approach for disease-related biomarkers is highly interesting and appealing. Herein, an ingenious visible light-induced membraneless self-powered PEC biosensing platform was constructed, integrating a signal amplification strategy for ultrasensitive split-type PEC bioanalysis. The system was comprised of a Bi₂S₃/BiPO₄ heterojunction photoanode and a platinum (Pt) cathode in a one compartment chamber. An alkaline phosphatase (ALP)-loaded sandwich immunoassay was used to generate the signal reporter ascorbic acid (AA) in a 96-well plate, and myoglobin (Myo) was used as a model protein. In the presence of AA, ferrocene (Fc), and Tris (2-carboxyethyl) phosphine (TCEP), the chemical-chemical redox cycling scheme was operated upon the initial oxidation of Fc by the holes in the Bi₂S₃/BiPO₄ photoelectrode, and Fc was regenerated from Fc⁺ by AA. Subsequently, AA was regenerated by TCEP after its oxidation, and cycling was triggered. As a result, the proposed self-powered PEC sensing exhibited excellent performance with a wide linear range from 5.0 × 10⁻¹³ to 1.0 × 10⁻⁷ g/mL, and a low detection limit of 2.0 × 10⁻¹³ g/mL for Myo. This work provided a new design of a redox cycling strategy in the self-powered PEC biosensor, and showed an effective approach for the clinical diagnosis.
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