Charge transport in purple membrane monolayers: A sequential tunneling approach

TL;DR

This paper proposes a sequential tunneling model to explain the electrical properties of proteins, specifically bacteriorhodopsin, and explores its potential for developing advanced nanobiosensors that mimic biological sensory functions.

Contribution

It introduces a microscopic sequential tunneling framework for protein charge transport, linking structure to electrical response and enabling sensor development.

Findings

Sequential tunneling explains I-V characteristics in proteins.

Protein structure directly influences electrical response.

Potential for new nanobiosensors mimicking biological sensors.

Abstract

Current voltage (I-V) characteristics in proteins can be sensitive to conformational change induced by an external stimulus (photon, odour, etc.). This sensitivity can be used in medical and industrial applications besides shedding new light in the microscopic structure of biological materials. Here, we show that a sequential tunneling model of carrier transfer between neighbouring amino-acids in a single protein can be the basic mechanism responsible of the electrical properties measured in a wide range of applied potentials. We also show that such a strict correlation between the protein structure and the electrical response can lead to a new generation of nanobiosensors that mimic the sensorial activity of living species. To demonstrate the potential usefulness of protein electrical properties, we provide a microscopic interpretation of recent I-V experiments carried out in bacteriorhodopsin at a nanoscale length.