Detection of abamectin residues by using optical MIP- ZIF67/Fe3O4/GQDs sensor

Detecting multiple pesticide residues in water is critical due to their risks to human and environmental health, which necessitates rapid and accurate methods. Given its high toxicity and persistence, accurately monitoring the widely used pesticide Abamectin in water is crucial. For this purpose, this study developed a molecularly imprinted polymer sensor based on magnetic metal-organic frameworks modified with graphene quantum dots (MIP-ZIF67/Fe₃O₄/GQDs) for the detection and determination of Abamectin. Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction spectroscopy (XRD), and vibrating sample magnetometer (VSM) analyses were used to characterize this polymer. The detection of abamectin pesticide was measured by fluorescence spectroscopy at different concentrations, and the polymer sensitivity was found to be 29.79 (a.u./ppm). Additionally, the detection limit and quantification limit of the prepared MIP-ZIF67/Fe₃O₄/GQDs were 160 (ppb) and 500 (ppb), respectively. The sensor demonstrated high specificity for Abamectin, with an imprinting factor (IF, α) of 2.52 and a relative selectivity coefficient ($k^{\prime }$, β) ranging from 5.82 to 8.17 against competing pesticides. Overall, a highly sensitive and selective molecularly imprinted polymer sensor (MIP-ZIF67/Fe₃O₄/GQDs) was developed to detect the toxic pesticide abamectin in water. Under optimal conditions, it achieved a 99.82 % trapping efficiency and a high recovery rate of 98.88 %, demonstrating excellent stability for environmental monitoring.