In situ Raman spectra of an NAD+-modified silver electrode at various potentials

At various potentials, the in situ confocal Raman technique was employed to detect SERS signals from a silver electrode surface modified with NAD+ through a self‐assembled monolayer (SAM) method. The SERS bands of the NAD+ molecule are much more sensitive to changes in the applied potential compared with experimental results reported previously. It is demonstrated in detail that the NAD+ molecules undergo reorientation at or desorption from the silver electrode surface with a potential shift from −0.5 to 0.0 V vs a saturated calomel electrode based on a charge‐transfer mechanism for explanation of the SERS signals. The effect of buffer electrolytes on the results of the SERS experiment was also investigated. Copyright © 2004 John Wiley & Sons, Ltd.