Uricase-free and cost-effective colorimetric assay for uric acid based on CoBTC metal-organic frameworks.

The development of enzyme-free uric acid (UA) detection methods remains challenging due to cost, stability, and sensitivity limitations. Here, we report a uricase-free colorimetric biosensor using cobalt-1,3,5-benzene tricarboxylate metal-organic frameworks (CoBTC MOFs) with intrinsic peroxidase-like activity. CoBTC catalyzes the oxidation of TMB by conducting H₂O₂ to blue oxTMB, while UA reduces oxTMB to colorless TMB, allowing for the quantification of UA via absorbance changes. This biosensor achieved a detection limit of 0.25 μM and a linear range of 0.4-180 μM, outperforming many uricase-dependent assays. Clinical validation with human serum (recovery: 98-103%, RSD < 3%) confirmed the resistance to matrix effects. This work provides a scalable and low-cost alternative for point-of-care UA monitoring in diagnostic settings.