Secondary Structure-Dependent Charge Transport in iLOV Protein Junctions

The composition and structure of proteins are crucial for charge migration in the solid-state charge transport (CTp). Despite much progress, it is still challenging to explore the relationship between conformational change and CTp in the complex protein system. Herein, we design three improved light-oxygen-voltage (iLOV) domains, and efficiently regulate the CTp of the iLOV self-assembled monolayers (SAMs) by pH induced conformation variation. The current density can be controlled in the range of one order of magnitude. Interestingly, the CTp of iLOV displays negative linear relations with the β-sheet contents. Single-level Landauer fitting and transition voltage spectroscopy analysis suggest that β-sheet-dependent CTp would be related to the coupling between iLOV and electrodes. This work proposes a new strategy to explore the CTp in complex molecular system. Our findings deepen the understanding on protein structure-CTp relationship, and provide predictive mode of protein CTp responses for the design of functional bioelectronics.