Electrochemical sensor for detection of uric acid using screen-printed electrodes modified with NiO/PANI-Graphene

Abstract

Uric acid (UA) is a product of the catabolism of purine bases (adenine and guanidine) of nucleic acids that occurs naturally in the human body. The analysis of UA plays an important role in diagnosing and treating diseases such as gout, kidney stones, diabetes, heart disease, and Lesch-Nyhan syndrome. UA is analysed in the laboratory by the enzymatic colorimetric method with a time consuming of approximately one hour. Currently, electrochemical sensors are considered as a potential approach in the rapid quantification of UA due to the advantages of rapid analysis, low cost, few samples required for analysis, compact design and easy to use and do not require highly skilled technicians like traditional analytical methods. In this study, a commercial printed electrode (SPE) was surface-modified with a polyaniline-graphene (PANI-Graphene) composite coating and functionalize the surface of a PANI-Graphene film with a NiO electrochemical catalyst by cyclic voltammetry (CV) method. The fabricated electrode (designated NiO/PANI-Graphene/SPE) was used for UA analysis in a simulated human fluid medium (PBS, pH 7.4). The results show that the NiO/PANI-Graphene/SPE sensor electrode has good electrocatalytic activity for the oxidation of UA in the potential range of 0.3 to 0.5 V. Characteristically, the sensor has a wide linear range in the concentration range of 10 to 1750 μM with a high sensitivity of 29.5 μA mM-1 cm-2 and a low detection limit of 5.00 μM (S/N = 3). The NiO/PANI-Graphene/SPE sensor electrode has potential applications in the development of non-enzymatic electrochemical sensors for the rapid quantification of UA content in human body fluids.