Direct electrochemistry of cytochrome c at modified Si(100) electrodes.
This paper demonstrates the direct electron transfer between the heme moiety of horse hearth cytochrome c and a pyridinyl group on self-assembled-monolayer-modified Si(100) electrodes. Self-assembled monolayers (SAMs) containing the putative receptor ligand were prepared by a step-wise procedure using "click" reactions of acetylene-terminated alkyl monolayers and isonicotinic acid azide derivatives. Unoxidized Si(100) electrodes, possessing either isonicotinate or isonicotinamide receptor ligands, were characterized using X-ray photoelectron spectroscopy, contact-angle goniometry, cyclic voltammetry, and electrochemical impedance spectroscopy. The ability of isonicotinic acid terminated layers to coordinatively bind the redox center of cytochrome c was found to be restricted to pyridinyl assemblies with a para-ester linkage present. The protocol detailed here offers an experimentally simple modular approach to producing chemically well-defined SAMs on silicon surfaces for direct electrochemistry of a well-studied model redox protein.
Ciampi
Simone
S
School of Chemistry, The University of New South Wales, Sydney, NSW 2052, Australia.
Gooding
J Justin
JJ
D000818:Animals; D001386:Azides / Q000737:chemistry*; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism; D004566:Electrodes; D004579:Electron Transport; D006418:Heme / Q000737:chemistry; D006736:Horses; D007700:Kinetics; D008024:Ligands; D015394:Molecular Structure; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D001386:Azides; D008024:Ligands; D011506:Proteins; D006418:Heme; D045304:Cytochromes c; D012825:Silicon