Preparation and characterization of functional metal–organic frameworks-coated extraction bars and their application in the simultaneous determination of pesticides in fetal bovine serum

Acute pesticide poisoning can cause several symptoms that threaten life safety, and the development of a rapid detection method is conducive to identifying toxicants early. In this work, we proposed a facile post-modification method to fabricate functional metal-organic frameworks (UIO-66-Py) with high specific surface area, stability and target recognition sites. UIO-66-Py-coated extraction bar could be fabricated by using PDMS as a “solid glue” to immobilize UIO-66-Py, where UIO-66-Py interpenetrated into PDMS uniformly to form functional film. The UIO-66-Py-coated extraction bar could work as an efficient solid-phase microextraction device for extraction of toxicants (pesticides) in the fetal bovine serum, which ascribed to great binding energy between UIO-66-Py and pesticides. Moreover, the immobilized membrane fabricated by PDMS would increase penetration of pesticides and diffusion path, thus promoting the retention of pesticides to afford more affinity sites for capturing pesticides. In addition, rotation speed, extraction time, elution solvent, and desorption time were investigated to achieve excellent recovery, and the corresponding optimal conditions were 200 rpm, 10 min, methanol, and 3 min, respectively. Through the established quantitative method, low limit of detections (LODs) of 0.15 − 0.37 ng/mL with relative standard deviations (RSDs) of less than 4.5 %, and linear correlation coefficients (R ) of 0.99 for these pesticides were achieved. The proposed on-site detection method exhibited an excellent performance with great sensitivity, anti-interference, and reusability, which demonstrated that synergistic effect from UIO-66-Py and PDMS facilitated highly sensitive detection and selective extraction. The findings in this work develop efficient detection methods for toxicants in biological sample and provide deep insights to further improve treatment efficiency of pesticide poisoning and afford a great potential in clinical point-of-care testing (POCT).