Development of Non-enzymatic Sensor for Uric Acid Detection Based on Gold Nanoparticles Electrodeposited on Laser-Induced Graphene Electrodes

Uric acid (UA) detection is a problem of great relevance, since this biomarker has been linked to diseases like gout, Diabetes Mellitus and Nephrolithiasis. Although clinical assays are available, the development of simple, accessible and low-cost methods for rapid UA detection is highly desirable. This work presents the development of a non-enzymatic electrochemical sensor for UA based on gold nanoparticles (AuNPs) electrodeposited on laser induced graphene (LIG) electrode. The materials were characterized by scanning electron microscopy (SEM) to verify the presence and morphology of AuNPs. The electrochemical characterization was carried out by cyclic voltammetry (CV) using (K3[Fe(CN6)]/K4[Fe(CN6)]) redox probe to evaluate the efficiency of surface modification stages. With optimized conditions, the LIG/AuNPs sensor showed a linear range from 1.68–16.81 mg/dL, a sensibility of 4.6919 µA/(mg/dL)cm2 (0.0788 µA/(µM * cm2)), a response time of 10 s, and a limit of detection (LOD) of 0.2098 mg/dL. Common interference of UA like glucose, urea and ascorbic acid showed negligible signals towards the designed LIG/AuNPs sensor. The simple design of the sensor and the achieved sensibility and selectivity showed that the proposed sensing platform could be a reliable tool for routine UA monitoring.