Molecularly imprinted polymer sheathed mesoporous silica tube as SPME fiber coating for determination of tobacco-specific nitrosamines in water

Application of Molecularly Imprinted Polymers in the Analysis of Explosives

The detection of explosives is highly important for the investigation of explosion cases and public safety management. However, the detection of trace explosive residues in complex matrices remains a major challenge. Molecularly imprinted polymers (MIPs), which mimic the antigen-antibody recognition mechanism, can selectively recognize and bind target explosive molecules. They offer advantages such as high efficiency, specificity, renewability, and ease of preparation, and they have shown significant potential for the efficient extraction and highly sensitive detection of trace explosive residues in complex matrices. This review comprehensively discusses the applications of MIPs in the analysis of explosives; systematically summarizes the preparation methods; and evaluates their performance in detecting nitroaromatic explosives, nitrate esters, nitroamine explosives, and peroxide explosives. Finally, this review explores the future potential of emerging technologies in enhancing the MIP-based analysis of explosives. The aim is to support the further application of MIPs in the investigation of explosion cases and safety management, providing more effective technical solutions for public safety.

Yolk-shell MOF-on-MOF hybrid solid-phase microextraction coatings for efficient enrichment and detection of pesticides: Structural regulation cause performance differences

Metal-organic frameworks (MOFs) based composites with different structure-activity relationships have been widely used in the field of organic pollutant adsorption and extraction. Here, two MOF-on-MOF composites with different structures (yolk-shell and core-shell) from homologous sources were prepared by a simple in-situ growth synthesis method and structural regulation. In order to verify the effect of composite structure on the extraction capacity, the adsorption performance of the yolk-shell structure (YS-NH2-UiO-66@CoZn-ZIF) and the core-shell structured (NH2-UiO-66@CoZn-ZIF) material were compared by using them as coating material of direct immersion solid-phase microextraction (DI-SPME) to enrich six pesticides in five matrices. The results showed that because of the unique hollow hierarchical structure, high specific surface area (930.68 m2 g-1), abundant and open active sites, and synergistic and complementary adsorption forces, YS-NH2-UiO-66@CoZn-ZIF composites had the maximum adsorption amount of 36.01-66.31 mg g-1 under the same experiment condition, which was 6.81%-34.26 % higher than that of NH2-UiO-66@CoZn-ZIF. In addition, the adsorption mechanism of the prepared materials was verified and elaborated through theoretical simulations and material characterization. Under the optimized conditions, the YS-NH2-UiO-66@CoZn-ZIF-coated SPME-HPLC-UV method had a wide linear range (0.241-500 μg L-1), a good linear correlation coefficient (R2 > 0.9988), a low detection limits (0.072-0.567 μg L-1, S/N = 3) and low quantification limits (0.241-1.891 μg L-1, S/N = 10). The relative standard deviations of individual fibers and different batches of fibers were 0.47-6.20 % and 0.22-2.48 %, respectively, and individual fibers could be recycled more than 104 times. This work provided a good synthetic route and comparative ideas for exploring the in-situ growth synthesis of yolk-shell composites with reasonable structure-activity relationships.