Innovative binding gels in diffusive gradients in thin film to detect hazardous contaminants: A critical review

This review extensively examines the utilization of diffusive gradients in thin-film (DGT) technology for evaluating hazardous contaminants in terrestrial and aquatic environments. It mainly probes the crucial role of binding gel materials in DGT devices, emphasizing the use of metal–organic frameworks (MOFs), and mixed hybrid nanomaterials in overcoming current challenges and improving DGT device efficiency. Specific types of binding gels are used for monitoring particular classes of contaminants such as DM-Fe₃O₄ nanoparticles (NP) for heavy metals, and XDA-1 for personal care products, XAD™18 for polyfluoroalkyl substances, TFN-CD for endocrine disruptors, MOF-derived porous carbon materials for antibiotics, ZIF-MOF/UiO-66 for drugs and heavy metals. Compared to traditional binding resins (Chelex®-100, Metsorb™, and ferrihydrite), these hybrid binding gels offer excellent advantages such as high selectivity and sensitivity, improved adsorption capacity, precision, higher elution efficiency, and better recyclability. Thus, these innovative hybrid binding resins are potential candidates for replacing existing binding gels in DGT devices under different environmental conditions.