Degradation Mechanism of Ag Nanorods for Surface Enhanced Raman Spectroscopy

This paper reports a degradation mechanism of silver (Ag) nanorods that are used as substrates for surface enhanced Raman spectroscopy (SERS). The attachment of sulfur and hydrocarbons to the surfaces of Ag nanorods is observed when they are stored in ambient over four months. This attachment is observed to correlate with ~20% decrease in SERS signal. The attachment, and thereby the signal degradation, takes three weeks to complete, and remains stable after the initial decay over the rest of the four month test period. While this degradation mechanism is a limitation to the gross enhancement, the ensuing stability beyond three weeks is encouraging.