Hampered by the absence of evidence and theoretical model of biological semiconductors, the unidirectional electron transport via the p-n junction between functional proteins and abiotic materials remains a challenge for bioelectronics. Bacteriorhodopsin (bR), a representative transmembrane protein, has demonstrated exceptional optoelectronic effects in bR/semiconductor hybrid materials and offers a possible pathway for addressing this challenge. In the present work, for the first time, bR is proved to be an n-type semiconductor with an indirect electron transition. Through the photo-electrochemical method used for studying the p-n junction effect in the bR and p-type semiconductor combined electrodes, we reached several important conclusions: The self-corrosion of bR integrated Cu2O electrodes is delayed for about 36 times; The photocurrent of bR integrated CuSCN electrodes is enhanced by about 400%, which is attributed to the directional migration of electrons via the p-n junction. Furthermore, the ultrafast kinetics we have explored, shows that the injection of electrons shortens the lifetime of the intermediate state O640 from 37.3 μs to 20.1 μs, what means that the protons transport rate accompanying the bR photocycle process is accelerated. Therefore, we believe that the concept of the bio-p-n junction and the mechanism of electron coupled proton transport, which are discussed herein, will promote useful research on bioelectronic applications for bR and its homologs.
|Journal||Biosensors and Bioelectronics|
|State||Published - 1 Feb 2021|
Bibliographical noteFunding Information:
This work is financially supported by grants from the National Natural Science Foundation of China (No. 51673006 , 51761145047 , 51422301 , 21722601 , 21373022 ) and the Fundamental Research Funds for the Central Universities .
© 2020 Elsevier B.V.
- Electron transport
- Proton transport