Electrochemical Detection of pH-Responsive Grafted Catechol and Immobilized Cytochrome c onto Lipid Deposit-Modified Glassy Carbon Surface

Estelle Lebegue (1) , Ricardo O. Louro (2) , F Barriere (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 NOVA - Universidade Nova de Lisboa = NOVA University Lisbon

The electrochemical systems of both grafted catechol as a pH-responsive electrophore and immobilized cytochrome c as a model redox protein are detected by cyclic voltammetry at an optimized lipid deposit-modified glassy carbon electrode. The catechol covalent grafting is successfully performed by the one-pot/three-step electrochemical reduction of 3,4-dihydroxybenzenediazonium salts generated in situ from 4-nitrocatechol. The resulting glassy carbon electrode electrochemically modified by grafted catechol species is evaluated as an efficient electrochemical pH sensor. The optimized molar ratio for the lipid deposit, promoting cytochrome c electrochemical activity in solution onto glassy carbon electrode, is reached for the lipid mixture composed of 75% 1,2-dioleoyl-sn-glycero-3-phosphocholine and 25% cardiolipin. Cytochrome c immobilization into the optimized supported lipid deposit is efficiently achieved by cyclic voltammetry (10 cycles) recorded at the modified glassy carbon electrode in a cytochrome c solution. The pH-dependent redox response of the grafted catechol and that of the immobilized cytochrome c are finally detected at the same lipid-modified glassy carbon electrode without alteration of their structure and electrochemical properties in the pH range 5-9. © 2018 American Chemical Society.

Domaines: Chimie

Estelle Lebegue, Ricardo O. Louro, F Barriere. Electrochemical Detection of pH-Responsive Grafted Catechol and Immobilized Cytochrome c onto Lipid Deposit-Modified Glassy Carbon Surface. ACS Omega, 2018, 3 (8), pp.9035-9042. ⟨10.1021/acsomega.8b01425⟩. ⟨hal-02299048⟩