Developing Activated Carbon Veil Electrode for Sensing Salivary Uric Acid

• Published in: Biosensors (Basel) 2021-08, Vol.11 (8), p.287
• Main Authors: Bukharinova, Maria A, Stozhko, Natalia Yu, Novakovskaya, Elizaveta A, Khamzina, Ekaterina I, Tarasov, Aleksey V, Sokolkov, Sergey V
• Format: Article
• Language: English
• Subjects: 3D material; Activated carbon; Alzheimer's disease; Antioxidants; Biomarkers; Biosensing Techniques; Capillary electrophoresis; Carbon; carbon paper; carbon veil; Charcoal; Charge transfer; Chromatography; Dielectric Spectroscopy; electrochemical activation; Electrochemical impedance spectroscopy; electrochemical nonenzymatic sensor; Electrochemical Techniques; Electrochemistry; Electrode polarization; Electrodes; Enzymes; Graphene; Humans; Lamination; Limit of Detection; Metal Nanoparticles; Nanomaterials; Nanotubes, Carbon; Oxidation; Oxidation-Reduction; Polyethylene terephthalate; Reagents; Saliva; Saliva - chemistry; Sensors; Sulfuric acid; Surface charge; Technology; Uric acid; Uric Acid - analysis; Voltammetry; X-ray spectroscopy
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios11080287

The paper describes the development of a carbon veil-based electrode (CVE) for determining uric acid (UA) in saliva. The electrode was manufactured by lamination technology, electrochemically activated and used as a highly sensitive voltammetric sensor (CVE ). Potentiostatic polarization of the electrode at 2.0 V in H SO solution resulted in a higher number of oxygen and nitrogen-containing groups on the electrode surface; lower charge transfer resistance; a 1.5 times increase in the effective surface area and a decrease in the UA oxidation potential by over 0.4 V, compared with the non-activated CVE, which was confirmed by energy dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, chronoamperometry and linear sweep voltammetry. The developed sensor is characterized by a low detection limit of 0.05 µM and a wide linear range (0.09-700 µM). The results suggest that the sensor has perspective applications for quick determination of UA in artificial and human saliva. RSD does not exceed 3.9%, and recovery is 96-105%. UA makes a significant contribution to the antioxidant activity (AOA) of saliva (≈60%). In addition to its high analytical characteristics, the important advantages of the proposed CVE are the simple, scalable, and cost-effective manufacturing technology and the absence of additional complex and time-consuming modification operations.