Nanostructured metal–organic framework-based luminescent sensor for chemical sensing: current challenges and future prospects

From its inception, an astonishing movement has been made in the architecture and fabrication of a fresh category of nanostructured material acknowledged as luminescent metal–organic frameworks (MOFs). Luminescent MOFs are self-assembled nanostructure by coordinating suitable metal cations or clusters and ideal organic linkers, which exhibited an abundance of merits for sensing of interest of analytes, such as chemicals, metal ions, biomarkers, etc. Herein, tunable surface morphology and diverse functionality of luminescent MOFs offer high sensitivity, high selectivity, good stability, recyclability, real-time applicability, etc. Additionally, the accessible porosity and luminescence property of nanostructured MOFs provides the transducing potential from host–guest chemistry to recognizable improvement in nanosize MOFs luminescence. Therefore, in this review article, we have summarized the nanostructured design of MOFs-based luminescent sensors for chemical and metal ions sensing. At first, the requirement of monitoring of chemical residues and metal ions exposure has been discussed that demonstrates the topical necessity for the chemical and metal ions recognition. Afterward, the current trends of MOFs-centered sensors, synthesis types, and their properties have been elaborated in brief. It revealed that several theoretical sensing mechanisms, such as electron transfer, energy transfer, ligand interaction, overlapping effect, oscillation effect, inner filter effect, decomposition, etc., are accountable for sensing of metal ions and chemical residues. The applications of nano-architectured MOFs-based luminescent sensors for chemical as well as metal ions sensing have been illustrated, which exhibit the lowest detection limit (μM–nM) for both metal ions and chemicals. Interestingly, the nanostructured MOFs relied on luminescent sensors that exhibited high sensitivity and selectivity for the chemical and metal ions in presence of diverse interfering substances. Surface functionality presented on the surface of nano-size MOFs, types of ligands, and selected metal ions provides precise recognition of real-time samples containing metal ions and chemicals. On the whole, the nanostructured design of a MOFs-based luminescent sensor will release a fresh preference for sensing of a target analyte. Nanostructured metal-organic frameworks based luminescent sensor for chemical and metal ions sensing