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Electrochemically Gated Long Distance Charge Transport in Photosystem I

submitted on 03.04.2019, 11:57 and posted on 04.04.2019, 16:11 by Montserrat López Martínez, Manuel López Ortiz, Maria Elena Antinori, Emilie Wientjes, Roberta Croce, Ismael Díez-Pérez, Pau Gorostiza

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 understand charge transport mechanisms, and to design 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. Here, we take advantage of electrochemical scanning tunneling microscopy (ECSTM) to control the Fermi energy 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.


BIST Ignite Program

European Union (SGA 720270)

Generalitat de Catalunya (CERCA and 2017-SGR-1442


MINECO (CTQ2016-80066R and FPI fellowship BES-2013-066430)


Email Address of Submitting Author


Institute for Bioengineering of Catalonia (IBEC)



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of Interest