Direct electrochemistry of glucose oxidase and sensing glucose using a screen-printed carbon electrode modified with graphite nanosheets and zinc oxide nanoparticles

Chelladurai Karuppiah, Selvakumar Palanisamy, Shen Ming Chen, Vediyappan Veeramani, Prakash Periakaruppan

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    47 Scopus citations

    Abstract

    We have studied the direct electrochemistry of glucose oxidase (GOx) immobilized on electrochemically fabricated graphite nanosheets (GNs) and zinc oxide nanoparticles (ZnO) that were deposited on a screen printed carbon electrode (SPCE). The GNs/ZnO composite was characterized by using scanning electron microscopy and elemental analysis. The GOx immobilized on the modified electrode shows a well-defined redox couple at a formal potential of −0.4 V. The enhanced direct electrochemistry of GOx (compared to electrodes without ZnO or without GNs) indicates a fast electron transfer at this kind of electrode, with a heterogeneous electron transfer rate constant (Ks) of 3.75 s−1. The fast electron transfer is attributed to the high conductivity and large edge plane defects of GNs and good conductivity of ZnO-NPs. The modified electrode displays a linear response to glucose in concentrations from 0.3 to 4.5 mM, and the sensitivity is 30.07 μA mM−1 cm−2. The sensor exhibits a high selectivity, good repeatability and reproducibility, and long term stability.

    [Figure not available: see fulltext.].

    Original languageBritish English
    Pages (from-to)1843-1850
    Number of pages8
    JournalMicrochimica Acta
    Volume181
    Issue number15-16
    DOIs
    StatePublished - 17 Oct 2014

    Keywords

    • Direct electrochemistry
    • Electrochemical activation
    • Glucose biosensor
    • Glucose oxidase
    • Graphite nanosheets
    • ZnO nanoparticles

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