Evaluation of the SERS performance of Ag nanoparticles immobilized on glass by silanes using protic or aprotic solvents

This work presents a comparative analysis of the SERS performance of silver nanoparticles (AgNP) immobilized on glass using the silane γ-aminopropil-trimethoxysilane (APTMS) for two situations: APTMS reacted from aqueous or toluenic solutions. The SERS performance has been evaluated for spatial homogeneity as a function of the number of AgNP deposition steps for 785 and 532 nm exciting radiations. It was verified that increasing the number of deposition steps improves the homogeneity only up to a certain level for each solvent, and additional deposition results in little gain in homogeneity.