An electrochemical ascorbic acid sensor based on palladium nanoparticles supported on graphene oxide

• Published in: Analytica chimica acta 2012-10, Vol.745, p.33-37
• Main Authors: Wu, Geng-huang, Wu, Yan-fang, Liu, Xi-wei, Rong, Ming-cong, Chen, Xiao-mei, Chen, Xi
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Anodic; Ascorbic acid; Ascorbic Acid - analysis; Chemistry; Dopamine - analysis; Electrical measurements; Electrochemical methods; Electrochemical sensor; Electrochemical Techniques - instrumentation; Electrochemical Techniques - methods; Electrodes; Exact sciences and technology; General, instrumentation; Graphene; Graphene oxide; Graphite - chemistry; Humans; Limit of Detection; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Oxides; Palladium; Palladium - chemistry; Palladium nanoparticles; Sensitivity and Specificity; Sensors; Uric Acid - analysis
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2012.07.034

[Display omitted] ► PdNPs with a mean diameter of 2.6nm were homogeneously deposited on GO. ► The proposed sensor exhibited a rapid amperometric response to AA within 5s. ► Good selectivity, wide linear range, low detection limit for AA. In this study, an electrochemical ascorbic acid (AA) sensor was constructed based on a glassy carbon electrode modified with palladium nanoparticles supported on graphene oxide (PdNPs-GO). PdNPs with a mean diameter of 2.6nm were homogeneously deposited on GO sheets by the redox reaction between PdCl42− and GO. Cyclic voltammetry and amperometric methods were used to evaluate the electrocatalytic activity towards the oxidation of AA in neutral media. Compared to a bare GC or a Pd electrode, the anodic peak potential of AA (0.006V) at PdNPs-GO modified electrode was shifted negatively, and the large anodic peak potential separation (0.172V) of AA and dopamine (DA), which could contribute to the synergistic effect of GO and PdNPs, was investigated. A further amperometric experiment proved that the proposed sensor was capable of sensitive and selective sensing of AA even in the presence of DA and uric acid. The modified electrode exhibited a rapid response to AA within 5s and the amperometric signal showed a good linear correlation to AA concentration in a broad range from 20μM to 2.28mM with a correlation coefficient of R=0.9991. Moreover, the proposed sensor was applied to the determination of AA in vitamin C tablet samples. The satisfactory results obtained indicated that the proposed sensor was promising for the development of novel electrochemical sensing for AA determination.