Published March 25, 2021 | Version Published
Journal article Open

Electrogeneration of a free-standing cytochrome c – silica matrix at a soft electrified interface

  • 1. The Bernal Institute and Department of Chemical Sciences, School of Natural Sciences, University of Limerick (UL), Limerick V94 T9PX, Ireland
  • 2. Université de Lorraine, CNRS, LCPME, F-54000 Nancy, France

Description

Interactions of a protein with a solid-liquid or a liquid-liquid interface may destabilise its conformation and hence result in a loss of biological activity. We propose here a method for the immobilisaiton of protein at an electrified liquid-liquid interface while maintaining it’s native conformation. Cytochrome c (Cyt c) is encapsulated in a silica matrix through an electrochemical process at an electrified liquid-liquid interface. Silica condensation is triggered by the interfacial transfer of cationic surfactant, cetyltrimethylammonium, at the lower end of the interfacial potential window. Cyt c is then adsorbed on the previously electrodeposited silica layer, when the interfacial potential is at the positive end of the potential window. By cycling the potential window back and forth, silica electrodeposition and Cyt c adsorption occurs sequentially as demonstrated by in situ UV-vis absorbance spectroscopy. After collection from the liquid-liquid interface, the Cyt c – silica matrix is characterised ex situ by UV-vis diffuse reflectance spectroscopy, confocal Raman microscopy and fluorescence microscopy, showing that the protein maintained its tertiary structure during the encapsulation process. The absence of denaturation is further confirmed in situ by the absence of electrocatalytic activity towards O2, signalling Cyt c denaturation. This method of protein encapsulation may be used for other proteins in the development of biphasic bioelectrosynthesis or bioelectrocatalysis applications.

Notes

The authors are grateful for travel support of the Irish Research Council and Campus France between the French and Irish groups through their joint ULYSSES programme. GH, MD and AW are grateful to the French Programme Investissement d'Avenir (PIA) "Lorraine Université d'Excellence" (Reference N° ANR-15-IDEX-04-LUE) and to the Agence Nationale de la Recherche (Hyperion project, grant number: ANR-14-CE14-0002-01) for partial funding of the research. AGQ acknowledges funding received from an Irish Research Council (IRC) Government of Ireland Postdoctoral Fellowship Award (Grant Number GOIPD/2018/252).

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Additional details

Funding

Designing Reactive Functionalised Soft Interfaces _ Self-healing soft materials for solar energy conversion, energy storage, and sustainable low cost hydrogen production 13/SIRG/2137
Science Foundation Ireland
SOFT-PHOTOCONVERSION – Solar Energy Conversion without Solid State Architectures: Pushing the Boundaries of Photoconversion Efficiencies at Self-healing Photosensitiser Functionalised Soft Interfaces 716792
European Commission