Optical Analysis of Cyclic Voltammetry of Ferrocenemethanol: A Comparative Study of SPR and LSPR.

This study integrates optical and electrochemical techniques to examine electrochemical activity at gold electrodes, focusing on the redox behavior of ferrocenemethanol as a model system. By combining Surface Plasmon Resonance (SPR) and Localized Surface Plasmon Resonance (LSPR) imaging with cyclic voltammetry (CV), spatial and electrochemical aspects of interfacial reactions are revealed. SPR provides broad-area sensitivity to refractive index changes, while LSPR offers high spatial resolution at the nanoscale. The incorporation of semioperational transformations into the analysis of voltametric data enhances the identification of electrochemical parameters and promotes more direct correlations between optical signals and underlying redox reaction mechanisms. In this work, LSPR is introduced as an electro-optical plasmonic method that has been relatively underexplored for redox probe behavior at the nanoscale, which confirms the well-established electrochemical-SPR approach. This comprehensive approach enriches the understanding of heterogeneous electron transfer processes, providing insights that can guide the development of advanced sensors, catalytic surfaces, and other electrochemical technologies.