Silver nanoparticles embedded cotton swab as surface-enhanced Raman scattering substrate combination of smartphone app for detection of carbofuran residues

Abstract

A surface-enhanced Raman scattering (SERS) substrate, consisting of a cotton swab with silver nanoparticles (AgNPs) embedded on common cotton, was fabricated in this study. The substrate consisted of AgNPs encapsulated in N-[3-(trimethoxysilyl)propyl]diethylenetriamine (ATS) hydrogels, and the resulting ATS-Ag SERS substrate presented good viscoelasticity, allowing it to conform to the surface of various materials of arbitrary roughness. The SERS peak intensity concentration change was rapidly captured and analyzed using a self-developed smartphone-based app system, which implements quantitative detection of carbofuran. The results showed that carbofuran can be detected with high sensitivity, with a linear range of 0.01–1.0 ppm and a detection limit of 0.05 ppm. In combination with a website, the proposed approach features high sensitivity, high simplicity of implementation, and a high throughput, which provides a promising means for the in situ determination of targets in practical applications.