“Self-assembled nanoscopic organic films with embedded copper ions, as models for redox-active proteins, studied by the method of cyclic voltamperometry”.

Annotation Our scientific group’s aim is to research the mechanism of processes that take place in the biological and model (biomimetic) systems at the atomistic level. The present master thesis describes the electron transfer exchange occurring between the Cu2+ ions which are immobilized in gold deposited L-cysteine self assembled monolayers (SAM) and the gold electrode. The present nanometer-size composite systems may be considered as the models of the redox-active globular proteins containing the copper ions such as laccase, azurin , ceruloplasmin and etc. According to the published data, which were obtained by a cyclic voltammetric method, electron exchange involving Cu2+ ions and gold electrode occurs by the single electron transfer ( n=1) mechanism, where there is no correlation among Cu2+ ions, as they participate independently during the whole process. Our researches revealed, that some interaction may occur among the L-cysteine immobilized copper ions at the high surface concentration of the Cu2+ ions, that leads to the formation of two dimensional nanometer-size clusters. Hence, several number of electrons (n=2, 4, 6, 10) could transfer synchronously. This phenomenon is revealed as the transformation of the single electron voltammetric signal (broad peaks) into multi electron voltammetric signal (narrow peaks). Furthermore, as the overall number of the immobilized Cu2+ ions does not change, the concentration of the active multi electron clusters are inversely proportional to the number of the synchronously transferred electrons.