Biosensing of purine derivatives using a pencil graphite electrode modified by copper: a promising tool in biomedicine
| Authors | |
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| Year of publication | 2014 |
| Type | Article in Proceedings |
| Conference | 15th International Conference on Electroanalysis |
| MU Faculty or unit | |
| Citation | |
| Field | Physical chemistry and theoretical chemistry |
| Keywords | copper nanoparticles; pencil graphite electrode; Cu(I)-purine complex; linear sweep voltammetry; elimination voltammetry |
| Description | Purine derivatives are important substances which can be found in blood, serum, urone and other physiological liquids as product of human biochemical processes known under the term purine catabolism. Here we suggest a simple, sensitive, easily accessible and very cheap tool for their electrochemical analysis - a pencil graphite elctrode (PeGE) modified by copper ions was performed by the reduction of Cu(II) from solution or by the oxidation of Cu(0) from nanoparticles immobilized on the electrode surface. Purine derivatives react with Cu(I) to form Cu(I)-puirne complexes which remain for s certain timr at the electrode surface. This time is used for the linear sweep voltammetric (LSV) experiment in an adsorptive stripping mode. The application of elimination voltammetry with linear scan (EVLS), which provides a special signal for a totally adsorptive electroactive species, allows increasing substantially the sensitivity evaluated by LOD from micromolar to units of nanomolar concentrations and separating overlapped purine signals. Moreover, the sensing can employ not only oxidation signals of purine derivatives but also oxidation signals of the corresponding copper complexes. These complexes were identified by means of titration of electrochemicallly produced cuprous ions by purine derivatives. The detection limits achieved by this approach are three orders of magnitude lower than those found with UV absorbance detection. As the detection does not require oxygen -free environment, our PeGE modified by monovalent copper may serve as a suitable electrochemical sensor for purines also in biomedicine. |
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