MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China.
Chemistry and Biochemistry Department, School of Science and Applied Technology, Laikipia University, Nyahururu, Kenya.
J Environ Sci Health B. 2021;56(3):222-234. doi: 10.1080/03601234.2020.1869476. Epub 2021 Jan 8.
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 and 2233 cm demonstrated a good linear fit with R=0.9738 and R=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.
表面增强拉曼散射（SERS）是一种快速检测农药残留的有前途的技术。然而，传统的 SERS 基底需要提取过程，既耗时又缺乏选择性、稳定性和重现性。在此，我们提出了一种多功能稳定的零价铁基核壳基底。它结合了磁分离、分子印迹技术的选择性吸附和 SERS 对carbaryl 的灵敏检测。核壳基底是通过将银固定在零价铁微球表面上成功制备的。随后在双金属磁性银微球上进行分子印迹，确保了选择性的去除和检测。该基底的饱和磁化强度为 8.89 emu/g，提供了高效的分析物分离。它对 carbaryl 的检测具有高灵敏度和选择性，可达到纳摩尔浓度水平。在拉曼位移 1599 cm 和 2233 cm 处的峰的线性回归模型分别表现出良好的线性拟合，R=0.9738 和 R=0.8952。该复合材料成功应用于加标水样，平均回收率为 89%。本研究的结果表明，该基底在分离和检测痕量化学污染物方面具有很大的应用潜力，可用于环境安全和保护。
