A unique fluorescence metal-organic framework for ultrasensitive fluorescent and colorimetric bimodal detection of phosphate.

Monitoring the concentration of phosphate is crucial for environmental protection and human health due to its severe ecological and health risks associated with elevated concentrations. Herein, a fluorescent-colorimetric bimodal nanoprobe based on the unique fluorescent metal-organic frameworks (Zr-PDI) has been developed for high-efficiency quantification of phosphate. The metal-oxygen coordination in Zr-PDI effectively diminished its fluorescence. However, the introduction of phosphate could weaken the metal-oxygen coordination interaction, leading to fluorescence recovery and absorption spectra changes of Zr-PDI. Taking advantage of these characteristics, Zr-PDI was exploited as a fluorescent-colorimetric bimodal detection tool for phosphate, offering excellent selectivity, a wide detection range, and high accuracy. Notably, the detection limit of fluorescence detection mode was as low as 0.023 μM, enabling ultrasensitive detection of phosphate. Furthermore, the Zr-PDI-based nanoprobe has achieved sensitive and reliable quantification of phosphate in Yong River and diabetic mouse serum samples. This proposed strategy provides a powerful, convenient, and practical tool for detecting phosphate in environmental and biological samples.