Lei Yang, Zhang Ziyi, Wang Cui, Song Rong-Bin, Li Zhaohui
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.
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.
Biosens Bioelectron. 2025 Nov 1;287:117732. doi: 10.1016/j.bios.2025.117732. Epub 2025 Jun 25.
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 TiO nanospheres and SbS/Au photoanode for initiating the release of TiO 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) of SPECs. Meanwhile, the DNA on the surfaces of these liberated TiO nanospheres can further hybridize with the hairpin DNA anchored on CuO/CuO photocathode, leading to the formation of type-II heterojunction and the negative shift of photocathode potential. Therefore, an additional decrease in the E 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.
探索信号放大策略是自供电光电化学生物传感器（SPEC）发展过程中的重要环节。在此，我们通过将Z型异质结释放的成分转移到相反的光电极上，开发了一种双电极协同信号放大模式，并将其与DNA熵驱动放大设计相结合，用于超灵敏SPEC生物分析。具体而言，模型分析物微小RNA-155触发熵驱动的DNA电路释放大量输出DNA，这些DNA可以与TiO纳米球和SbS/Au光阳极之间的部分互补DNA双链竞争性杂交，从而引发TiO纳米球的释放。在这种情况下，光阳极上形成的Z型异质结将受到破坏，导致光阳极电位正向移动，从而使SPEC的开路电压（E）降低。同时，这些释放的TiO纳米球表面的DNA可以进一步与锚定在CuO/CuO光阴极上的发夹DNA杂交，导致II型异质结的形成和光阴极电位的负向移动。因此，可以实现SPEC的E的额外降低，以进行级联信号放大。这项工作从双电极协同的角度为信号放大策略家族增添了新成员，这将在SPEC领域甚至其他基于燃料电池的生物传感器领域吸引更多关注。
