Induced surface enhancement in coral Pt island films attached to nanostructured Ag electrodes

TL;DR

This study demonstrates surface-enhanced Raman signals from platinum island films on nanostructured silver electrodes, highlighting the role of nanostructure and coating imperfections in enhancing spectroscopic signals.

Contribution

It introduces a novel method of inducing surface enhancement in platinum films on nanostructured silver, showing the impact of nanostructure and coating quality on Raman signal enhancement.

Findings

SE(R)R signals of molecules attached to Pt are up to 50% of those on Ag.

Non-perfect Pt coating enhances SE(R)R activity.

Metal type has minor influence on SE(R)R intensity.

Abstract

Coral Pt islands films are deposited via electrochemical reduction on silica coated nanostructured Ag electrodes. From these devices surface enhanced (resonance) Raman [SE(R)R] signals of molecules exclusively attached to Pt are obtained with intensities up to 50% of the value determined for Ag. SE(R)R spectroscopic investigations are carried out with different probe molecules, silica coating thicknesses and excitation lines. Additionally, field enhancement calculations on Ag-SiO2-Pt support geometries are performed to elucidate the influence of the Pt island film nanostructure on the observed Raman intensities. It is concluded that the non perfect coating of the Pt island film promotes the efficiency of the induced Pt SER activity. Comparison with similar measurements on Ag-SiO2-Au electrodes further suggests that the chemical nature of the deposited metal island film plays a minor role for the SE(R)R intensity.