Non-contact spectral analysis of cytochrome c on carbon electrodes with optical waveguide spectroscopy

Abstract

To realize the spectral analysis of molecules on the opaque substrate, we proposed non-contact optical waveguide (NOW) spectroscopy. The cyt.c was adsorbed on the carbon substrate by dipping method. This was fixed above the optical waveguide. The gap between the carbon substrate and the waveguide was controlled by latex beads with a diameter of 120 nm as a spacer. A clear NOW spectrum based on the adsorbed cyt.c on the carbon substrate was observed. The cyt.c was easily adsorbed on the carbon surface with an oxidized form by the dipping method. The electrochemical cell system constructed on the waveguide enabled the dynamic analysis on the redox reaction of the adsorbed cyt.c on the carbon electrode. The adsorbed cyt.c showed stable redox reaction without the dislocation or re-dissolution in an aqueous solution.