Suggestion of electrochemical sensors for microanalysis of content of copper in biological samples

There have been published several papers on voltammetric ultra-trace determination of some nucleic bases in the presence of Cu(II) using a mercury electrode or solid amalgam electrodes. Carbon electrodes can be used for the same purposes. The aim of this work was to employ the behaviour of purines in the presence of Cu(II) to determine these metal ions. Primarily we aimed on investigation of basic electrochemical behaviour of detection copper at hanging mercury drop and carbon paste electrodes by using of cyclic and differential pulse voltammetry. Thanks to formation of the complex adenine-Cu(II) under the specific conditions the peak of this complex was measured at -0.6 V. The detection limit (3 S/N) for Cu(II) ions was estimated as 5 nM. By using of this approach we were able to determine the content of copper in animal tissues even at tens of nM. Moreover we utilized suggested approach to monitor the level of copper ions in samples of blood serum of patients with metabolic disorder.