Zr-based metal organic framework nanoparticles coated with a molecularly imprinted polymer for trace diazinon surface enhanced Raman scattering analysis

Abstract

In this study, a new surface imprinted polymer of type MOFs–MIPs was synthesized with diazinon as the template and a Zr-based metal organic framework (UiO-67) as the matrix for trace diazinon surface enhanced Raman scattering (SERS) analysis in environmental water samples. The material was characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and N₂ sorption analysis. Additionally, batch experiments were carried out to investigate the rebinding ability for diazinon by SERS. The results showed that the MOFs–MIPs showed a fast kinetic, high rebinding capacity, good selectivity, and excellent sensitivity (limit of detection = 3.6 nM) for diazinon, with good linear relationships of 10 nM–1.0 mM. Furthermore, the pseudo-second-order model and Langmuir adsorption isotherm are well fitted with the experimental data, indicating chemical adsorption might be the rate-limiting step. Moreover, the relative selectivity coefficients of the MOFs–MIPs for diazinon/acephate, diazinon/metham and diazinon/basta are 141.6, 160.3 and 142.8, respectively, indicating the high selectivity of MOFs–MIPs towards diazinon. The MOFs–MIPs could be used for at least 6 runs, indicating its favorable stability and reusability. Finally, real water samples were successfully analyzed with the MOFs–MIPs and high recoveries varying from 92.7% and 108.2% were obtained. Overall, the MOFs-MIPs possessed high affinity, high selectivity and sensitivity for daizinon detection in real water samples by SERS.