Structural, thermal and electrochemical analysis of in vitro grown urinary stone type uric acid crystal
摘要
Uric acid (C5H4N4O3) crystallization plays a critical role in urolithiasis, affecting millions globally, yet its electrochemical properties remain underexplored. This study integrates structural, spectroscopic, thermal and electrochemical characterization of in vitro grown uric acid crystals, establishing quantitative structure–property relationships. Uric acid crystals were grown via a single diffusion gel growth technique (pH 5, Specific density 1.04 g/cm3) and harvested after 21 days. X-ray diffraction confirmed a monoclinic structure (space group P21/a) with a crystallite size of 26 ± 2 nm and a low dislocation density of 1.47 ± 0.15 × 10− 3 nm− 2, indicating high crystalline quality. FESEM showed radially arranged rectangular rods with a uniform elemental composition (C:40.80%, N:32.39%, O:26.81%). FTIR and FT-Raman spectroscopy confirmed characteristic Carbonyl and hydroxyl functional groups with hydrogen bonding. UV–Visible spectroscopy indicates a band gap of 5.05 eV Thermogravimetric analysis revealed a 72% mass loss at 600 °C with an activation energy of 138.37 ± 0.63 kJmol− 1 for conversion to cyanuric acid and carbonaceous products. The novelty lies in the electrochemical profiling, cyclic voltammetry showed irreversible oxidation at 0.54 V with a specific capacitance of 37.1 ± 2.3 F/g, while impedance spectroscopy provided charge transfer resistance (9.3 kΏ). The integration of structural and electrochemical data revealed that low microstrain correlates with high charge transfer resistance, suggesting crystalline perfection impedes electrochemical kinetics. These findings provide insight into the stone formation mechanism and potential diagnostic biomarkers for differentiating urolithiasis. This study emphasizes the importance of understanding the properties of uric acid crystals for developing diagnostic and therapeutic strategies.
Graphical Abstract