Transferring the released component of Z-scheme heterojunction onto opposite photoelectrode: A dual-electrode-cooperating signal amplification strategy in photo fuel cell for self-powered biosensing

Yang Lei; Ziyi Zhang; Cui Wang; Rong-Bin Song; Zhaohui Li

doi:10.1016/j.bios.2025.117732

Transferring the released component of Z-scheme heterojunction onto opposite photoelectrode: A dual-electrode-cooperating signal amplification strategy in photo fuel cell for self-powered biosensing

Biosens Bioelectron. 2025 Jun 25:287:117732. doi: 10.1016/j.bios.2025.117732. Online ahead of print.

Authors

Yang Lei¹, Ziyi Zhang¹, Cui Wang¹, Rong-Bin Song², Zhaohui Li³

Affiliations

¹ Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Institute of Analytical Chemistry for Life Science, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China.
² Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Institute of Analytical Chemistry for Life Science, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China; School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China. Electronic address: rbsong@zzu.edu.cn.
³ Zhengzhou Key Laboratory of Functional Nanomaterial and Medical Theranostic, Henan Joint International Research Laboratory of Green Construction of Functional Molecules and Their Bioanalytical Applications, Institute of Analytical Chemistry for Life Science, College of Chemistry, Zhengzhou University, Zhengzhou, 450001, China. Electronic address: zhaohui.li@zzu.edu.cn.

PMID: 40580740
DOI: 10.1016/j.bios.2025.117732

Abstract

Exploration of signal amplification strategy is an important link during the development of self-powered photoelectrochemical biosensors (SPECs). Herein, we develop a dual-electrode-cooperating signal amplification mode by transferring the released component of Z-scheme heterojunction onto opposite photoelectrode, and integrate it with DNA entropy-driven amplification design for ultrasensitive SPECs bioanalysis. Specifically, microRNA-155, the model analyte triggers the entropy-driven DNA circuit to release large amounts of output DNAs, which can competitively hybridize with the partial complementary DNA double strand between TiO₂ nanospheres and Sb₂S₃/Au photoanode for initiating the release of TiO₂ nanospheres. In this case, the formed Z-scheme heterojunction on photoanode will suffer destruction, generating a positive shift of photoanode potential and thus a decrease in the open circuit voltage (E^OCV) of SPECs. Meanwhile, the DNA on the surfaces of these liberated TiO₂ nanospheres can further hybridize with the hairpin DNA anchored on CuO/Cu₂O photocathode, leading to the formation of type-II heterojunction and the negative shift of photocathode potential. Therefore, an additional decrease in the E^OCV of SPECs can be realized for cascading signal amplification. This work adds a new member to the family of signal amplification strategies from dual-electrode-cooperating perspective, which will attract more attentions in the field of SPECs and even other fuel cells-based biosensor.

Keywords: Dual-electrode cooperation; Heterojunction conversion; Self-powered photoelectrochemical biosensors; Signal amplification strategy; Ultrasensitive analysis.