Selective and sensitive detection of dimethyl phthalate in water using ferromagnetic nanomaterial-based molecularly imprinted polymers and SERS

Abstract

To overcome the complicated pretreatment, low selectivity and low sensitivity detection associated with the detection of dimethyl phthalate (DMP), this study synthesized ferromagnetic nanomaterials that coupled with surface enhanced Raman scattering (SERS) and molecular imprinting polymers (MIPs). The pretreatment process can be simplified by ferromagnetic nanomaterials, then Fe₃O₄@SiO₂@Ag@MIPs selectively adsorbing DMP can be achieved, and SERS can be applied for DMP detection with high sensitivity. As a control, the non-imprinted polymers (NIPs) Fe₃O₄@SiO₂@Ag@NIPs were synthesized. Adsorption experiments results showed that the saturation adsorption amounts of Fe₃O₄@SiO₂@Ag@MIPs is 36.74 mg/g with 40 mg/L DMP and Fe₃O₄@SiO₂@Ag@NIPs is 17.45 mg/g. For DMP, Fe₃O₄@SiO₂@Ag@MIPs have a greater affinity. In addition, after seven adsorption-desorption cycles the Fe₃O₄@SiO₂@Ag@MIPs are reusable with approximately a 9.8 % loss in adsorption capacity. With an 8.7 × 10⁻⁹ M detection limit, DMP detection was performed by SERS, which revealed that the Raman intensities of the associated characteristic peak were linearly proportional to the DMP concentrations. As a result, the recovery rate of the testing artificial water varied from 87.9 % to 117 %. These outcomes show that the suggested technique for finding DMP in actual water samples is practical.