Paper coated with silver nanoflower composite, a dual substrate for SERS and PS-MS
Recently a novel dual substrate for both SERS and PS-MS based on the deposition of silver nanoflowers (AgNFs) onto a paper-based analytical device (PAD) has been developed. Although the obtention of the substrate requires several steps, it is possible to synthesize a bunch of them at the same time. Figure 1 illustrates the different stages involved in the synthesis process of the so-called ny-AgNF PADs (further details are included in the full article). To obtain the silver nanoflowers, an already described protocol was followed, which is based on a simple reaction involving silver nitrate and ascorbic acid as the reducing agent (Figure 1, steps 4-7). Furthermore, previous modification of the paper was needed to anchor the nanoflowers to its surface (Figure 1, steps 1-3, and 8). First, a coating of nylon-6 was needed to assure the surface availability of the analytes in Surface-enhanced Raman spectroscopy ( SERS). Next, a surface of metallic silver was acquired by the deposition of