Photoinduced modification of quantum dot optical properties affects bacteriorhodopsin photocycle in a (quantum dot)- bacteriorhodopsin hybrid material

V A Krivenkov,K I Brazhnik,I R Nabiev,E P Lukashev,A A Chistyakov,G E Kotkovskiy,D O Solovyeva,P S Samokhvalov

doi:10.1088/1742-6596/541/1/012045

Abstract

A method for controlled changes in the radiative properties of quantum dots (QDs) in order to modulate the Forster resonance energy transfer (FRET) rate in nano-hybrid materials is proposed. The mechanism underlying the effect of QDs with optical properties modulated by UV laser irradiation on the photocycle of the photosensitive protein bacteriorhodopsin (bR) in its native purple membranes (PM) isolated from Halobacterium salinarum has been studied. The irradiation leads to a twofold decrease in the QD fluorescence quantum yield without changes in the extinction spectrum or the position or shape of the fluorescence spectrum. The bR photocycle is accelerated, which has been shown to be related to the changes of the surface potential of PM upon formation of their complexes with QDs.

Highlights

The photosensitive protein bacteriorhodopsin [1], a photosensitive membrane protein from purple membranes (PMs) of Halobacterium salinarium, is a promising potential component of photovoltaic nano–bio hybrid structures [2] which utilizes as little as 0.1–0.5% of the total energy of the solar light optical spectrum [3]
In [6] was found that the integration of quantum dots (QDs) into purple membranes (PMs) containing bR could accelerate the formation of the intermediate M-form of the bR photocycle
It can be done by UV laser irradiating which reduce the quantum yield of QDs without affecting the structure of the QD-PM nano-hybrid system

Summary

Introduction

The photosensitive protein bacteriorhodopsin (bR) [1], a photosensitive membrane protein from purple membranes (PMs) of Halobacterium salinarium, is a promising potential component of photovoltaic nano–bio hybrid structures [2] which utilizes as little as 0.1–0.5% of the total energy of the solar light optical spectrum [3]. The harvesting and utilization of solar energy by photosensitive proteins can be made substantially more efficient by complexing them with semiconductor nanocrystals or quantum dots (QDs), which are capable of absorbing light in the UV and visual spectral regions and passing the absorbed energy to the photosensitive proteins through the Förster resonance energy transfer (FRET) mechanism [4, 5].

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