| Abstract
| - To combine voltammetric techniques with surface-enhanced resonance Raman scattering (SERRS), cytochromec (cyt c) was immobilized on a roughened silver electrode chemically modified with a self-assembled monolayer(SAM) of 4-mercaptopyridine (PySH). All measurements were performed on the same electrode in a homemadespectroelectrochemical cell suitable for such applications. Cyt c on a PySH-SAM shows a quasi-reversible, monoelectronic,adsorption-controlled CV response with a formal reduction potential of −0.061 V (vs SCE), which is comparable tothe values found for native cyt c adsorbed on different SAMs. SERRS spectra proved that cyt c adsorbed on a PySHmonolayer is present in the native conformer (the B1 state). Voltammetric and SERRS experiments at high ionicstrength revealed that the interaction between the SAM and the protein is electrostatic in nature. In conclusion, PySHwas found to be suitable for adsorption of cyt c at SERRS-active silver surfaces. In comparison with other SAMs,PySH requires less time (10 min vs 12−18 h) to form a long-time durable and reproducible coating on the roughenedelectrode surface.
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