Stationary photocurrent generation from bacteriorhodopsin-loaded lipo-polymersomes in polyelectrolyte multilayer assembly on polyethersulfone membrane.
Anal Bioanal Chem
; 412(24): 6307-6318, 2020 Sep.
Article
em En
| MEDLINE
| ID: mdl-32166446
ABSTRACT
Vesicles constructed of either synthetic polymers alone (polymersomes) or a combination of polymers and lipids (lipo-polymersomes) demonstrate excellent long-term stability and ability to integrate membrane proteins. Applications using lipo-polymersomes with integrated membrane proteins require suitable supports to maintain protein functionality. Using lipo-polymersomes loaded with the light-driven proton pump bacteriorhodopsin (BR), we demonstrate here how the photocurrent is influenced by a chosen support. In our study, we deposited BR-loaded lipo-polymersomes in a cross-linked polyelectrolyte multilayer assembly either directly physisorbed on gold electrode microchips or cross-linked on an intermediary polyethersulfone (PES) membrane covalently grafted using a hydrogel cushion. In both cases, electrochemical impedance spectroscopic characterization demonstrated successful polyelectrolyte assembly with BR-loaded lipo-polymersomes. Light-induced proton pumping by BR-loaded lipo-polymersomes in the different support constructs was characterized by amperometric recording of the generated photocurrent. Application of the hydrogel/PES membrane support together with the polyelectrolyte assembly decreased the transient current response upon light activation of BR, while enhancing the generated stationary current to over 700 nA/cm2. On the other hand, the current response from BR-loaded lipo-polymersomes in a polyelectrolyte assembly without the hydrogel/PES membrane support was primarily a transient peak combined with a low-nanoampere-level stationary photocurrent. Hence, the obtained results demonstrated that by using a hydrogel/PES support it was feasible to monitor continuously light-induced proton flux in biomimetic applications of lipo-polymersomes. Graphical abstract.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polímeros
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Sulfonas
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Bacteriorodopsinas
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Halobacterium salinarum
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Membranas Artificiais
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article