Assembling PVP-Au NPs as portable chip for sensitive detection of cyanide with surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) with the advantages of providing fingerprint information of target molecules and single-molecules sensitivity has been widely used in on-site analysis; however, the SERS measurements always suffer from the problem of the stability of substrates.

Here, the polyvinylpyrrolidone (PVP)-stabilized Au NPs (PVP-Au NPs) have been assembled through the simple, convenient evaporation-induced strategy with the large-scale hotspots substrates. The presence of PVP can not only facilitate the assembly of Au NPs but also prevent the corrosion of CN− towards the Au NPs with the formation of [Au (CN)2]−1, providing high stable and reproducible SERS signals. Moreover, the PVP-Au NPs have been assembled on the Si wafer to fabricate the portable SERS chip for rapid on-site detection of CN− with an RSD of 5.8% and limitation of 100 ppb.