Silanized Reduced Graphene Oxide as an Effective Modified Electrode to Minimize Fouling during Uric Acid Detection

Electrode fouling is a daunting challenge during the electrochemical detection of uric acid (UA), particularly in complex biological environments. Herein, silanized reduced graphene oxide was explored as an antifouling platform to modify glassy carbon electrode (GCE) for the electrochemical detection of UA. Silanization imparts less polarity to the rGO surface upon introducing bulky siloxane groups that effectively minimizes non-specific adsorption of biomolecules. In order to evaluate the impact of different silane molecules on the antifouling performance, three different silanes, namely, triethoxymethylsilane (TEMS), dodecyltrimethoxysilane (DTMS), and trimethoxyphenylsilane (TMPS), were employed individually for rGO functionalization. Of these modified electrodes, rGO-TEMS/GCE and rGO-TMPS/GCE showed superior electrochemical responses toward UA, with rGO-TMPS/GCE exhibiting enhanced resistance to both electrochemical fouling and biofouling. rGO-TMPS/GCE maintained a stable current response after 1 h of incubation in a solution containing effective foulants such as bovine serum albumin (BSA) and cytochrome c (Cyt c). As a result, rGO-TMPS/GCE was further employed for the detection of UA by differential pulse voltammetry (DPV). The modified electrode exhibited a limit of detection of 0.76 μM ± 0.14 (N = 3), with a sensitivity of 1.04 μA μM^-1 cm^-2. These results emphasize the usefulness of rGO-TMPS/GCE as an effective antifouling electrode material for the stable and sensitive detection of UA.