Facile synthesis of UOx-doped Cu2O@HP-HKUST-1 for sensitive colorimetric detection of uric acid

Abstract

Uric acid (UA) is the final catabolism product of purines, which widely exist in various body fluids, including serum and urine. The accurate and sensitive detection of UA is essential for health monitoring and diagnosing many diseases. Herein, a hybrid structure urate oxidase (UOx)-doped Cu₂O@HP-HKUST-1 material was proposed for colorimetric and ratiometric detection of UA. In the presence of UOx, the decomposition of UA can produce H₂O₂, which was then catalyzed by Cu₂O@HP-HKUST-1 into ˙OH radicals. The ˙OH radicals could then oxidize 3,3′,5,5′-tetramethylbenzidine (TMB), as evidenced by a UV-vis absorption peak at 652 nm. Finally, a biosensor based on UOx-Cu₂O@HP-HKUST-1 was employed to determine UA levels in urine samples. The linear range was 5–600 μM and the limit of detection for colorimetric detection of UA was 2.58 μM.