Detection of Purine Metabolite Uric Acid with Picolinic-Acid-Functionalized Metal-Organic Frameworks.

Uric acid (UA) is a purine metabolite closely related to the metabolic function of human. Fluorescence analysis is a very effective method because of its high selectivity and sensitivity, but it still remains a great challenge for direct UA detection. In this work, a fluorescent sensor based on postfunctionalized metal-organic frameworks (UiO-PSM) was designed focusing on the direct detection of UA. UiO-PSM was synthesized from a zirconium-based metal-organic framework (UiO-66-NH2) and 2-picolinic acid through an amidation reaction. Because UA could quench the fluorescence of UiO-PSM through coordination, hydrogen bonding, and π-π interactions, the sensor could detect UA directly. UiO-PSM exhibited the advantages of short reaction time, high selectivity, high sensitivity, and wide linear range for UA detection. This work provided a novel method for UA detection and had potential application values in clinical diagnosis.