Metal-organic framework-based off-on fluorescent probe for highly selective and sensitive phosphate detection

The escalating demand for versatile and precise diagnostic tools across various biomedical applications has led to the development of an advanced assay utilizing a fluorescent metal-organic framework (MOF). Our novel approach centers on the synthesis of a controlled-explosive NH₂-MIL-53(Fe) MOF, composed of trivalent iron ions and 2-aminoterephthalic acid. This framework possesses the unique capability to produce explosively enhanced fluorescence upon environmental triggers such as phosphate conditions, where it disintegrates to release intensely fluorescent molecules. The surface of NH₂-MIL-53(Fe) MOF was further functionalized with poly(acrylic acid-co-maleic acid) polymers (PAAcoMA) to form PAAcoMA@MIL-53(Fe) MOF, thereby enhancing its stability. The presence of phosphate ions is detected by the degree of fluorescence resulting from the unquenching of PAAcoMA@MIL-53(Fe) MOF. This system demonstrates not only high sensitivity but also a broad dynamic range, making it suitable for phosphate ion detection. This innovative technology holds promise for significant advancements in the field of phosphate indicator-based biosensing, with potential applications in the development of PCR kits, thereby supporting a wide range of diagnostic and therapeutic applications.