A Nano‐Biohybrid‐Based Bio‐Solar Cell to Regulate the Electrical Signal Transmission to Living Cells for Biomedical Application

Bio‐solar cells are studied as sustainable and biocompatible energy sources with significant potential for biomedical applications. However, they are composed of light‐harvesting biomolecules with narrow absorption wavelengths and weak transient photocurrent generation. In this study, a nano‐biohybrid‐based bio‐solar cell composed of bacteriorhodopsin, chlorophyllin, and Ni/TiO2 nanoparticles is developed to overcome the current limitations and verify the possibility of biomedical applications. Bacteriorhodopsin and chlorophyllin are introduced as light‐harvesting biomolecules to broaden the absorption wavelength. As a photocatalyst, Ni/TiO2 nanoparticles are introduced to generate a photocurrent and amplify the photocurrent generated by the biomolecules. The developed bio‐solar cell absorbs a broad range of visible wavelengths and generates an amplified stationary photocurrent density (152.6 nA cm−2) with a long lifetime (up to 1 month). Besides, the electrophysiological signals of muscle cells at neuromuscular junctions are precisely regulated by motor neurons excited by the photocurrent of the bio‐solar cell, indicating that the bio‐solar cell can control living cells by signal transmission through other types of living cells. The proposed nano‐biohybrid‐based bio‐solar cell can be used as a sustainable and biocompatible energy source for the development of wearable and implantable biodevices and bioelectronic medicines for humans. A nano‐biohybrid‐based bio‐solar cell capable of absorbing a broad range of visible wavelengths and generating an amplified photocurrent density is developed to verify the possibility of its biomedical application. The electrophysiological signals of muscle cells at the neuromuscular junction are regulated precisely by motor neurons excited by the photocurrent of the bio‐solar cell upon light irradiation.