A Sensitive Surface‐enhanced Raman Scattering Method for Determination of Melamine with Aptamer‐modified Nanosilver Probe

TLDR: In this article, a nanosilver-aptamer (AgssDNA) SERS probe was used for the determination of melamine in milk, and the increased SERS intensity ΔI240 cm−1 is linear to melamine concentration in the range of 6.3-403.6 μg·L−1, with a detection limit of 1.2 μg·l−1.

Abstract: The small nanosilver was prepared by the sodium borohydride procedure. The aptamer was used to modify nanosilver to obtain a nanosilver-aptamer (AgssDNA) SERS probe for the determination of melamine. In pH 6.6 phosphate buffer solution and in the presence of NaCl, the AgssDNA probe specifically combined with melamine to release nanosilver particles that were aggregated to nanosilver clusters, which exhibited SERS effect at 240 cm−1. When melamine concentration increased, the nanosilver clusters increased, and the SERS intensity at 240 cm−1 increased. The increased SERS intensity ΔI240 cm−1 is linear to melamine concentration in the range of 6.3–403.6 μg·L−1, with a detection limit of 1.2 μg·L−1. This assay was applied to determination of melamine in milk, with satisfactory results.