Flexible Substrate of Cellulose Fiber/Structured Plasmonic Silver Nanoparticles Applied for Label-Free SERS Detection of Malathion

Abstract

Surface-enhanced Raman scattering (SERS) is considered an efficient technique providing high sensitivity and fingerprint specificity for the detection of pesticide residues. Recent developments in SERS-based detection aim to create flexible plasmonic substrates that meet the requirements for non-destructive analysis of contaminants on curved surfaces by simply wrapping or wiping. Herein, we reported a flexible SERS substrate based on cellulose fiber (CF) modified with silver nanostructures (AgNS). A silver film was fabricated on the membrane surface with an in situ silver mirror reaction leading to the formation of a AgNS–CF substrate. Then, the substrate was decorated through in situ synthesis of raspberry-like silver nanostructures (rAgNS). The SERS performance of the prepared substrate was tested using 4-mercaptobenzoic acid (4-MBA) as a Raman probe and compared with that of the CF-based plasmonic substrates. The sensitivity of the rAgNS/AgNS–CF substrate was evaluated by determining the detection limit of 4-MBA and an analytical enhancement factor, which were 10 nM and ~107, respectively. Further, the proposed flexible rAgNS/AgNS–CF substrate was applied for SERS detection of malathion. The detection limit for malathion reached 0.15 mg/L, which meets the requirements about its maximum residue level in food. Thus, the characteristics of the rAgNS/AgNS–CF substrate demonstrate the potential of its application as a label-free and ready-to-use sensing platform for the SERS detection of trace hazardous substances.

Rapid detection of residual chlorpyrifos and pyrimethanil on fruit surface by surface- enhanced Raman spectroscopy integrated with deep learning approach

“…Raman spectroscopy has attracted much attention due to its nondestructive analytical ability, and it can provide rich information about the chemical components, structures, molecular vibrations and interactions of the measured samples (Adya & Canetta, 2014). Especially, due to the development of surface-enhanced Raman spectroscopy (SERS), Raman spectroscopy is now widely used in many elds (Kitaw et al, 2023;Serebrennikova et al, 2023;Sindhu & Manickavasagan, 2023;Wang et al, 2023). Actually, SERS has been employed to detect trace pesticide residues in foods (Xiao et al, 2023;Yu et al, 2023).…”