A Novel Approach to Fabricating a Screen-Printed Electrode Based on a Gold Nanorod–Graphene Oxide Composite for the Detection of Uric Acid †

In this study, we report the development of a technique to fabricate a screen-printed electrode (SPE) and apply it in uric acid sensing. The SPE was fabricated by printing it on a photo paper substrate using a printing technique on an office printer. In particular, the conductive ink used to print the working electrode (WE) and counter electrode (CE) consisted of graphene oxide (GO) and a gold nanorod (AuNR) material. While the reference electrode (RE) was made by applying a conductive silver paste to the fabricated SPE, the electrochemical measurement of uric acid solution using fabricated SPE GO/AuNR provided a higher signal than commercially available SPE. The electroanalytical performance of the fabricated SPE based on GO/AuNR, which was used to measure the uric acid solution, exhibited a linear range of 0.8−200 μM, a detection limit of 0.5 μM, a quantitation limit of 1.0 μM, an outstanding repeatability (% relative standard deviation) of 4.885%, and good selectivity with ascorbic acid, dopamine, glucose, urea, and sodium as interference. Furthermore, an SPE, fabricated based on GO/AuNR, was successfully employed for the determination of uric acid concentration in human urine samples using the standard addition approach.