Nickel Single-Atom Catalyst-Mediated Efficient Redox Cycle Enables Self-Checking Photoelectrochemical Biosensing with Dual Photocurrent Readouts

作者：Tan, Rong; Qin, Ying; Liu, Mingwang; Wang, Hengjia; Li, Jinli; Luo, Zhen; Hu, Liuyong^*; Gu, Wenling^*; Zhu, Chengzhou^*

来源：ACS Sensors, 2023, 8(1): 263-269.

DOI：10.1021/acssensors.2c02125

• single-atom catalysts
• photoelectrochemical biosensing
• photocurrent polarity switching
• self-checking
• acetylcholinesterase activity assay

Developing a self-checking photoelectrochemical biosensor with dual photocurrent signals could efficiently eliminate false-positive or false-negative signals. Herein, a novel biosensor with dual photocurrent responses was established for the detection of acetylcholinesterase activity. To achieve photocurrent polarity-switchable behavior, the iodide/tri-iodide redox couple was innovatively introduced to simultaneously consume the photoexcited electrons and holes, which circumvents the inconvenience caused by the addition of different hole-and electron-trapping agents in the electrolyte. Importantly, benefiting from the high catalytic activity, the enhanced photoelectric responsivity can be realized after decorating the counter electrode with nickel single-atom catalysts, which promotes a more efficient iodide/ tri-iodide redox reaction under low applied voltages. It is envisioned that the proposed photocurrent polarity switching system offers new routes to sensitive and reliable biosensing.

• 单位
  武汉工程大学