In this work, a simple and highly selective electrochemical biosensor for determination of uric acid (UA) is synthesized by using β-lactoglobulin (BLG)-functionalized multiwall carbon nanotubes (MWCNTs) and a platinum nanoparticles (PtNPs) nanocomposite. Urate oxidase (UOx) can oxidize uric acid to hydrogen peroxide and allantoin, which provides a good opportunity for electrochemical detection for UA. Under the optimized conditions, the current changes by the UOx/Bull Serum Albumin (BSA)/BLG-MWCNTs-PtNPs/Glassy Carbon (GC) electrode with the electrochemical method was proportional to the concentration of UA. According to experiments, we obtained a linear response with a concentration range from 0.02 to 0.5 mM and achieved a high sensitivity of 31.131 μA mM-1 and a low detection limit (0.8 μΜ). Meanwhile, nanoparticles improved the performance of the biosensor and combined with BLG not only prevented the accumulation of composite nanomaterials, but also provided immobilization of uricase through electrostatic adsorption. This improves the stability and gives the constructed electrode sensing interface superior performance in UA detection.
Keywords: multiwall carbon nanotubes; nanocomposite; urate oxidase; uric acid biosensor; β-lactoglobulin.