Core-shell magnetic Ag-molecularly imprinted composite for surface enhanced Raman scattering detection of carbaryl.

Emily C Cheshari, Xiaohui Ren, Xin Li

Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes 2021

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Surface-enhanced Raman scattering (SERS) is a promising technique for rapid detection of pesticide residues. However, conventional SERS substrates require extraction processes which are time consuming and they also lack selectivity, stability and reproducibility. Herein, we present a multifunctional stable zero-valent iron based core-shell substrate. It combines magnetic separation, selective adsorption by molecular imprinting technique and sensitive detection of carbaryl by SERS. The core-shell substrate was successfully prepared by immobilizing silver on the surface of zero-valent iron microspheres. Subsequent molecular imprinting on the bimetallic magnetic silver microspheres ensured selective removal and detection. The substrate exhibited magnetization saturation of 8.89 emu/g providing efficient analyte separation. It showed high sensitivity and selectivity toward carbaryl detection to nanomolar concentration level. Linear regression models for peaks at Raman shift 1599 cm-1 and 2233 cm-1 demonstrated a good linear fit with R2=0.9738 and R2=0.8952 respectively. The composite was successfully applied on spiked water samples resulting in average recovery rate of 89%. The findings of this study demonstrate great substrate potential for application in separation and detection of trace quantities of chemical contaminants for environment safety and protection.

Citation

Emily C Cheshari, Xiaohui Ren, Xin Li. Core-shell magnetic Ag-molecularly imprinted composite for surface enhanced Raman scattering detection of carbaryl. Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes. 2021;56(3):222-234