The development of cobalt(II) phthalocyanine–cobalt(II) tetra(5-phenoxy-10,15,20-triphenylporphyrin), (CoPc–(CoTPP)[subscript 4]) pentamer as a novel redox mediator for amperometric enzyme electrode sensitive to glucose is described. A glassy carbon electrode (GCE) was first modified with the pentamer, then followed by the immobilization onto the GCE–CoPc–(CoTPP)[subscript 4] with glucose oxidase (GOx) through cross-linking with glutaraldehyde in the presence of bovine serum albumin (BSA) and Nafion® cation-exchange polymer. The proposed biosensor displayed good amperometric respose charateristics to glucose in pH 7.0 PBS solution; such as low overpotentials (+400 mV versus Ag|AgCl), very fast amperometric response time (~5 s), linear concentration range extended up to 11 mM, with 10 μM detection limit. The biosensor exhibited electrochemical Michaelis–Menten kinetics and showed an average apparent Michaelis–Menten constant (K′M) of 14.91 ± 0.46 mM over a storage period of 2 weeks.
| Identifer | oai:union.ndltd.org:Rhodes/oai:eprints.ru.ac.za:437 |
| Date | 15 July 2006 |
| Creators | Ozoemena, K.I., Nyokong, T. |
| Source Sets | Rhodes University SA |
| Detected Language | English |
| Type | Article, PeerReviewed |
| Format | application/pdf |
| Relation | http://dx.doi.org/10.1016/j.electacta.2006.03.055, http://eprints.ru.ac.za/437/ |
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