Dual model biosensor integrated with peroxidase-like activity and self-assembly for uric acid detection†

Uric acid (UA), the final product of purine metabolism, is a crucial biomarker for gout diagnostics and highly related to various metabolic diseases. Precise detection of UA levels in serum and urine enables disease diagnosis and guides treatment. Combining the advantages of colorimetry and laser desorption/ionization mass spectrometry (LDI-MS), we developed a dual-model biosensor based on hollow Cu₂O@Au nanocubes (h-Cu₂O@Au NCs) for UA detection. The h-Cu₂O@Au NCs demonstrated excellent peroxidase (POD)-like activity and were used to rapidly detect UA by colorimetric assay, with a linear range of 0.05–2 mM and limit of detection (LOD) of 35.71 μM. Moreover, the h-Cu₂O@Au NCs achieved enrichment and detection of UA via the liquid–liquid interface self-assembly-assisted LDI-MS, with a linear range of 0.01–0.5 mM, LOD of 15.6 μM, and reproducibility of <5%. In view of its advantages, the dual-model nanoplatform based on h-Cu₂O@Au NCs achieved UA detection in serum samples by colorimetry assay and in urine samples by LDI-MS, obtaining results consistent with the commercial UA assay kit (72–511 μM for serum, R² = 0.956 and 2–9 mM for urine, R² = 0.876), presenting potential in the rapid and sensitive detection of UA in clinic.