Study of Adsorption Behavior of Uric Acid on Gold Nanoparticles

Hyperuricemia is commonly associated with gout, diabetes, stroke, coronary heart disease, uric acid (UA) nephrolithiasis, and renal dysfunction. It can induce kidney damage, exacerbate atherosclerosis, and accelerate the onset and progression of cardiovascular and cerebrovascular diseases. In this study, a coreduction method with tannic acid and trisodium citrate dihydrate was utilized to synthesize spherical gold nanoparticles (AuNPs) with a size of 4.10 nm-13.77 nm in diameter. The toxicity of these nanoparticles on human normal pulmonary epithelial cells (BEAS-2B) was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2<i>H</i>-tetrazolium (MTS) method. Owing to their nontoxicity and excellent adsorption performance, AuNPs were employed as an adsorbent for adsorbing UA. The effect of adsorption conditions including pH, temperature, and time on adsorption rate was investigated using single-factor experiment and orthogonal experiment. This result indicates that the factors influencing the adsorption rate of UA on AuNPs, in descending order, are pH (A) > time (C) > temperature (B) and that the optimal adsorption rate of UA on AuNPs is 77.93% at pH 2.00 and 50 °C for 5 h. The adsorption rate of AuNPs to UA is 11.37 ± 0.21% at pH 7.40 and 37 °C for 3 h. In addition, the adsorption mechanism of UA on AuNPs at 50 and 37 °C was discussed.