Silver-nanoparticle-grafted silicon nanocones for reproducible Raman detection of trace contaminants in complex liquid environments

Abstract

Super-hydrophobic delivery (SHD) is an efficient approach to enrich trace analytes into hot spot regions for ultrasensitive surface-enhanced Raman scattering (SERS) detection. In this article, we propose an efficient and simple method to prepare a highly-uniform SHD-SERS platform of high performance in trace detection, named as “silver-nanoparticle-grafted silicon nanocones” (termed AgNPs/SiNC) platform. It is fabricated via droplet-confined electroless deposition on the super-hydrophobic SiNC array. The AgNPs/SiNC platform allows trace analytes enriched into hot spots formed by AgNPs, leading to an excellent reproducibility and sensitivity. The relative standard deviation (RSD) for detecting R6G (10−7 M) is down to 4.70% and the lowest detection concentration for R6G is 10−14 M. Moreover, various contaminants in complex liquid environments, such as, crystal violet (10−9 M) in lake water, melamine (10−7 M) in liquid milk and methyl parathion (10−7 M) in tap water, can be detected using the SERS platform. This result demonstrates the great potential of the AgNPs/SiNC platform in the fields of food safety and environmental monitoring.