Electrochemically Gated Long‐Distance Charge Transport in Photosystem I. (5th August 2019)

• Record Type: Journal Article
• Authors: López‐Martínez, Montse; López‐Ortiz, Manuel; Antinori, Maria Elena; Wientjes, Emilie; Nin‐Hill, Alba; Rovira, Carme; Croce, Roberta; Díez‐Pérez, Ismael; Gorostiza, Pau
• Is Part Of: Angewandte Chemie. Volume 131:Number 38(2019)
• Page Start: 13414
• Page End: 13418
• Publication Date: 2019-08-05
• Subjects: Elektrochemisches Gating -- Elektronentransfer -- Photosynthese -- Rastertunnelmikroskopie -- Stromabklingen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201904374
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The transport of electrons along photosynthetic and respiratory chains involves a series of enzymatic reactions that are coupled through redox mediators, including proteins and small molecules. The use of native and synthetic redox probes is key to understanding charge transport mechanisms and to the design of bioelectronic sensors and solar energy conversion devices. However, redox probes have limited tunability to exchange charge at the desired electrochemical potentials (energy levels) and at different protein sites. Herein, we take advantage of electrochemical scanning tunneling microscopy (ECSTM) to control the Fermi level and nanometric position of the ECSTM probe in order to study electron transport in individual photosystem I (PSI) complexes. Current–distance measurements at different potentiostatic conditions indicate that PSI supports long‐distance transport that is electrochemically gated near the redox potential of P700, with current extending farther under hole injection conditions. Abstract : Mittels elektrochemischer Rastertunnelmikroskopie (ECSTM) wurde der Elektronentransport in einzelnen Photosystem‐I(PSI)‐Komplexen direkt gemessen. Dabei stellte sich heraus, dass die Abstandszerfallsrate β in der Nähe des Redoxpotentials von P700 elektrochemisch gesteuert ist und die Stromstärke sich zur Lochinjektion in PSI noch weiter erstreckt.