In this work, we developed a label-free, homogeneous surface-enhanced Raman-scattering (SERS) platform for the rapid, simple and sensitive detection of Ag + by using the unmodified gold nanoparticles (AuNPs). It utilizes the different absorption properties of single-strand DNA (ssDNA) and double-strand DNA (dsDNA) on citrate-coated AuNPs and specific interactions between Ag + and cytosine-cytosine pairs. In the presence of Ag + , the structure of ssDNA containing rich cytosine will form a duplex, resulting in the salt-induced aggregation of gold nanoparticles; the corresponding SERS signal transduction can be observed due to the plasmonic coupling of metallic nanoparticles. The assay possesses a superior signal-to-background ratio as high as ~35.8 with a detection limit of 15 nM. This approach is not only rapid and convenient in operation, but also shows excellent selectivity, which makes it possible to detect Ag + in actual samples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.