No abstract

An electrochemical glucose sensor based on a screen-printed diamond electrode was fabricated as a low-cost, disposable, and sensitive electrode. Amperometric detection of glucose was achieved by using a glucose-oxidase-immobilized cobalt phthalocyanine/boron-doped diamond powder (GOx-CoPc/BDDP)-printed electrode, with a linear calibration curve in the concentration range of 0.2–1.0 mM. The background current for the GOx-CoPc/BDDP-printed electrode stabilized faster than that for the GOx-CoPc/carbon-printed electrode, which confirms its practical usefulness for the detection of glucose at low concentrations.

Electrochemical detection of glucose was achieved at a glucose oxidase (GOx)-cobalt phthalocyanine (CoPc)-modified borondoped diamond (BDD) electrode without any additional electron mediator in the electrolyte solution. The surface of the hydrogen-terminated BDD thin film prepared by microwave plasma-assisted CVD was modified with 4-vinylpyridine (4VP) via photochemical modification. The 4VP-BDD was then immersed in a CoPc solution to obtain CoPc-BDD. A poly(pphenylenediamine) (PPD) thin film containing GOx was coated on the CoPc-BDD electrode surface via electropolymerization. At the GOx/PPD-CoPc-BDD electrode, anodic current for glucose oxidation was observed with a sigmoidal voltammetric curve, indicating successful electron mediation of H 2 O 2 generated as the result of glucose oxidation at GOx. The signal-to-background ratio for voltammetric current of glucose detection was larger at the GOx/PPD-CoPc-BDD electrode than at the GOx/PPDmodified platinum electrode due to the smaller background current of the modified BDD electrode.