Smartphone-based ratiometric fluorescent definable system for phosphate by merged metal-organic frameworks

Phosphate plays an important role in a wide range of chemical and biological processes, so the development of a new phosphate optical sensor with high sensitivity, specificity and visual recognition function has important practical significance. Herein, a ratiometric fluorescent (RF) probe and a smartphone-integrated colorimetric test paper sensing platform for assay phosphate was fabricated using hybrid fluorescent UiO-66-NH2 and Eu3+@MOF-808 metal-organic frameworks. After continuous addition of phosphate, the blue fluorescence emission of UiO-66-NH2 and the red emission of Eu3+@MOF-808 were regularly enhanced and quenched respectively, and the fluorescence response of the detection platform to phosphate exhibited a dear color change process (red -> pink -> blue). More importantly, the probe solution and test paper of the integrated smartphone are converted to digital values through RGB channels and successfully used to visualize semi-quantitative recognition of phosphate. In addition, an RF probe and a smartphone integrated fluorescent test paper were developed separately to devise logic gate devices for detecting phosphate. The multifunctional ratio sensing platform integrated by the smartphone furnishes a new strategy and broad prospects for the intelligent online identification of important targets in biological samples and environmental samples. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The development of a new phosphate optical sensor is of great practical significance. A ratiometric fluorescent probe and a smartphone-integrated colorimetric test paper sensing platform were successfully fabricated for detecting and recognizing phosphate. This innovative sensing platform provides a new strategy for intelligent online identification of important targets in biological and environmental samples.