Potential dependent thiocyanate adsorption on gold electrodes: a comparison study between SERS and SHINERS

Potential dependent adsorption of target molecules on electrode surface has long been analyzed by several analytical techniques at the electrochemical interfaces. Here, the adsorption of thiocyanate (SCN⁻) on gold electrodes [Au (111) and Au (poly)] is investigated by electrochemical shell isolated nanoparticle‐enhanced Raman spectroscopy (EC‐SHINERS) and surface‐enhanced Raman spectroscopy. Based on the experimental observation, C − N stretching mode of N‐bound SCN⁻ can be observed around 2080 cm⁻¹ throughout the whole potential range. The band corresponding to ν_C−N of S‐bound SCN⁻ appears as a shoulder at more negative potentials, and as a well‐defined band are more positive potentials. However, the overlapped bands provoke a negative shift in the frequency of S‐bound thiocyanate. Therefore, a change in the calculated Stark slope is observed. Interestingly, SHINERS has been employed to demonstrate the thiocyanate orientation and its effect on Raman spectra. Our results widen the opportunities of SHINERS to unravel the potential‐dependent adsorption behavior of target molecules on single‐crystal electrode surfaces. Copyright © 2016 John Wiley & Sons, Ltd.