Electrochemical evaluation of total antioxidant capacities in fruit juice based on the guanine/graphene nanoribbon/glassy carbon electrode

• Published in: Talanta (Oxford) Vol. 106; pp. 206 - 211
• Main Authors: Yang, Yan, Zhou, Jiawan, Zhang, Hejing, Gai, Pengbo, Zhang, Xiaohua, Chen, Jinhua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.03.2013
• Subjects: Antioxidants - analysis; Ascorbic Acid; Beverages; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Electrochemical Techniques; Electrodes; Fruit - chemistry; graphene nanoribbon; Graphite - chemistry; Guanine; Guanine - chemistry; Humans; Hydroxyl radical; Hydroxyl Radical - chemistry; Limit of Detection; Nanotubes, Carbon - chemistry; Reference Standards; Reproducibility of Results; Total antioxidant capacities; graphene nanoribbon; Ascorbic acid; Guanine; Hydroxyl radical; Total antioxidant capacities
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2012.12.030

Based on electro-immobilization of guanine on graphene nanoribbon (GNR) modified glassy carbon (GC) electrode, a new electrochemical DNA biosensor was developed for the evaluation of total antioxidant capacities (TAC) in fruit juices. The biosensor relies on the guanine damage that is induced by hydroxyl radical (·OH) generated by Fenton-type reaction. Ascorbic acid (AA), which has the ability to scavenge the ·OH and to protect the guanine immobilized on the electrode surface, was used as the standard antioxidant to evaluate the TAC in fruit juice. Under optimized conditions, the proposed biosensor has excellent analytical performance for antioxidant capacity assessment: wide linear range (0.1 to 4mgL−1), high sensitivity (4.16μA/mgL−1) and low detection limit (0.05mgL−1). Compared with the other electrochemical sensors developed previously, the proposed electrode demonstrates the improved detection limit of about 5 times to one order of magnitude for antioxidant capacity assessment. Additionally, the biosensor was successfully applied to the determination of the TAC in fruit juices. ► Electrochemical detection of total antioxidant capacities with graphene nanoribbons. ► The biosensor relies on the guanine damage that is induced by hydroxyl radical (·OH). ► The developed electrode shows good analytical performance.