Stationary current generated from photocycle of a hybrid bacteriorhodopsin/quantum dot bionanosystem

Abstract

Bacteriorhodopsin (bR) is a promising biomaterial for broad potential applications in optical and optoelectronic devices. Upon the original photochemical cycle of bR, for the first time we construct a hybrid bR/quantum dot (QD) bionanosystem and a stationary current is generated from the modified photocycle. We propose a model to explain that QDs could act as nanoscaled light sources embedded in bR to assist its generation of a stationary photocurrent, which is completely different from the reported transient spikes from the bR’s photocycle. It opens the horizon for optical devices other than those reported up to date.

Extracellular microbial synthesis of biocompatible CdTe quantum dots

“…Hydrothermally synthesized CdTe QDs were manufactured according to our previous reports [12,19,20]. In our biosynthesis E. coli was grown with aeration at 37°C in Luria-Bertani (LB) medium, a mixture containing 10 g peptone, 5 g yeast extract and 10 g l À1 NaCl, pH 7.0.…”

“…Over the past two decades QDs of different sizes, shapes and compositions [3][4][5][6] have been extensively studied for practical applications, such as fluorescent biological labels [7,8], optoelectronic transistor components [9] and solar cells [10]. Among various QDs, cadmium telluride (CdTe) nanocrystals have attracted significant attention for energy, electronics and biomedical applications [9,[11][12][13] because of their tunable sizedependent emission within the whole visible range. In comparison with conventional fluorescent dyes, CdTe QDs provide the advantages of high photostability, controllable and narrow emission bands and a high quantum yield.…”

Bio-nano hybrid materials based on bacteriorhodopsin: Potential applications and future strategies

“…with negatively charged QDs [77,[79][80][81]. Bio-affinity interaction is created between streptavidin-coated QD and biotin-labeled bR or PM by natural affinity of streptavidin to biotin [77,82].…”

Quantum Dot-Based Nanocomposites for Biomedical Applications

“…This emission from the excited QDs has been proposed to be involved in the protein state change that further contributes to the new pattern of photocurrent [145]. Light absorption of Bacteriorhodopsin, a protein component of the cytoplasmic membrane of Halobacterium salinarum, has been shown to trigger a change in protein conformation that results in light-driven proton transportation from the cytoplasmic to the extracellular side of the membrane.…”