Electrochemical Localized Surface Plasmon Resonance: Review and Theoretical Consideration

An overview of the current state of research in the field of electrochemical localized surface plasmon resonance (electrochemical LSPR, ELSPR) is presented. The model based on the Mie scattering theory for spherical particles and the Stern electrical double layer theory were exploited for computer modelling of the influence of parameters of the “gold nanoparticle-electrolyte” system on the extinction spectra and the LSPR position of a gold nanoparticle upon applying an electric potential difference between the nanoparticle and the surrounding electrolyte in the range of −0.3 to +0.6 V. It was shown that the extinction spectra undergo non-linear and mostly non-monotonic shifts in intensity and wavelength depending on the magnitude of the applied potential at all nanoparticle sizes in the radius range of 5–80 nm. It was established that the resulting shift in the LSPR position with changes in potential difference in the range of −0.3 to +0.6 V depends on the size of the nanoparticle, the refractive index of the electrolyte, the concentration of the electrolyte, the potential of zero charge of the nanoparticle in the electrolyte, and the charge of the ion in the electrolyte, and can reach amplitude values from 0.3 nm to 5.6 nm.