Chen Zhongxin, McCuskey Samantha R, Zhang Weidong, Yip Benjamin Rui Peng, Quek Glenn, Jiang Yan, Ohayon David, Ong Shujian, Kundukad Binu, Mao Xianwen, Bazan Guillermo C
Institute for Functional Intelligent Materials (I-FIM), National University of Singapore, Singapore, Singapore.
Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, Singapore, Singapore.
Nat Commun. 2025 Jul 1;16(1):5955. doi: 10.1038/s41467-025-61086-5.
Living biophotovoltaics represent a potentially green and sustainable method to generate bio-electricity by harnessing photosynthetic microorganisms. However, barriers to electron transfer across the abiotic/biotic interface hinder solar-to-electricity conversion efficiencies. Herein, we report on a facile method to improve interfacial electron transfer by combining the photosynthetic cyanobacterium Synechococcus elongatus PCC 7942 (S. elongatus) with a conjugated polyelectrolyte (CPE) atop indium tin oxide (ITO) charge-collecting electrodes. By self-assembly of the CPE with S. elongatus, soft and semitransparent S. elongatus/CPE biocomposites are formed with three-dimensional (3D) conductive networks that exhibit mixed ionic-electronic conduction. This specific architecture enhances both the natural and mediated exoelectrogenic pathway from cells to electrodes, enabling improved photocurrent output compared to bacteria alone. Electrochemical studies confirm the improved electron transfer at the biotic-abiotic interface through the CPE. Furthermore, microscopic photocurrent mapping of the biocomposites down to the single-cell level reveals a ~ 0.2 nanoampere output per cell, which translates to a 10-fold improvement relative to that of bare S. elongatus, corroborating efficient electron transport from S. elongatus to the electrode. This synergistic combination of biotic and abiotic materials underpins the improved performance of biophotovoltaic devices, offering broader insights into the electron transfer mechanisms relevant to photosynthesis and bioelectronic systems.
活体生物光伏是一种利用光合微生物产生生物电的潜在绿色可持续方法。然而，跨非生物/生物界面的电子转移障碍阻碍了太阳能到电能的转换效率。在此，我们报道了一种简便的方法，通过将光合蓝藻聚球藻PCC 7942（聚球藻）与共轭聚电解质（CPE）结合在氧化铟锡（ITO）电荷收集电极上，来改善界面电子转移。通过CPE与聚球藻的自组装，形成了具有三维（3D）导电网络的柔软且半透明的聚球藻/CPE生物复合材料，该网络表现出混合离子-电子传导。这种特定结构增强了从细胞到电极的自然和介导的胞外电子生成途径，与单独的细菌相比，能够提高光电流输出。电化学研究证实了通过CPE在生物-非生物界面处电子转移得到改善。此外，对生物复合材料进行单细胞水平的微观光电流映射显示，每个细胞的输出约为0.2纳安，这相对于裸露的聚球藻提高了10倍，证实了从聚球藻到电极的有效电子传输。生物和非生物材料的这种协同组合支撑了生物光伏器件性能的提升，为与光合作用和生物电子系统相关的电子转移机制提供了更广泛的见解。
