Boric acid-functionalized lanthanide metal-organic framework used as a ratiometric fluorescence probe for uric acid detection

Exploring high-performance fluorescent strategies for the highly sensitive determination of uric acid (UA) is of great importance for the early diagnosis of hyperuricemia. Herein, we constructed a simple and greatly sensitive ratiometric fluorescence sensor based on boric acid-functionalized lanthanide metal-organic framework (BA-Eu-MOF) for the determination of UA in complex environments. In this strategy, BA-Eu-MOF with dual-emission was first prepared by a one-step method at room temperature. It acts as a signal tag, allowing the sensor not only to exhibit a fast fluorescence response but also to generate an inverse response signal. This can be attributed to the inner filter effect, which enables amplification of the fluorescence signal and demonstrates satisfactory photostability, sensitivity and anti-interference capability. Benefiting from the efficient dual-channel strategy, BA-Eu-MOF sensor displayed a wide linear range (0–160 mg/L) for UA with a lower detection limit (0.06 mg/L). Moreover, the sensor has been successfully applied to the determination of UA in urine with satisfactory results. Accordingly, the developed ratiometric fluorescence sensors exhibit simple, fast, low-cost and highly sensitive properties that provide a reference for the detection of UA in complex clinical systems.