In this work, we present a systematic study on solid Surface Enhanced Raman Scattering
(SERS) substrates consisting of Au and Ag nanoparticles (NPs) loaded on filter paper with the
dip-coating method. The aim of this work is to explore how a series of parameters (e.g., concentration
of colloidal solution, different porosity of filter paper, and the presence of an aggregating agent)
affects the analytical performance of paper-based SERS substrates. All the substrates developed in this
study have been analyzed with two non-resonant probe molecules, 4-mercaptobenzoic acid (4-MBA)
and adenine, in terms of (i) inter-sample repeatability, (ii) intra-sample repeatability, (iii) sensitivity,
and (iv) overall SERS performance in terms of analyte quantification. Moreover, the issue of how to
evaluate the repeatability for a solid SERS substrate is carefully discussed.
