Preparation of nanoflower-based loaded dual nanozymes and their application in colorimetric detection of uric acid in urine

Abstract

A one-pot bio-inspired synthesis approach was employed to fabricate five types of uricase nanoflowers (UOx-NFs), from which Mn-UOx-NFs with the highest catalytic activity were selected. The Mn-UOx-NFs were successfully integrated with magnetic-responsive Fe₃O₄@CeO₂ quantum dots to create efficient loaded dual nanozymes (LDNs). The LDNs demonstrated excellent temperature and storage stability. After being reused 7 times, 18.5% of the enzymatic activity was still retained. Based on the LDNs, a reusable and sensitive colorimetric method for the detection of uric acid in urine was established. The colorimetric detection system exhibited a good linear relationship between uric acid concentration and optical density values at 652 nm within the range of 1–55 µmol L⁻¹, with a detection limit of 0.37 µmol L⁻¹.