Study of Electrochemistry of L-Homocysteine/Copper Complexes on Gold Electrode by Cyclic Voltammetry

Author: Lasha Nakashidze
Co-authors: Nakashidze Lasha, Davitashvili Kakha, Khoshtariya Dimitri, Nioradze Nikoloz
Keywords: Nanostructure, L-Homocysteine, Cyclic Voltammetry
Annotation:

The charge transfer in exclusively label metal ion containing bio-electrochemical nanosized multifunctional complexes, and the changes in their structural and physical characteristics, amplify the interest of interdisciplinary research in these systems. The aggregation and precipitation of extra-cellular β-amyloid peptides is the fundamental reason causing Alzheimer’s disease. This pathological process is characterized by the redox-stressed phenomenon, and the latter one is summoned by the coordination of Cu2+ ions with β-amyloid peptide. The presented work contains fundamental research, which involves interphasic, complex systems, such as carbon-containing nano-structural redox-active imitators (copper ions ensnared in peptides). In this research we focused on copper (II) amino acid complexes, more specifically, Cu(II)/L-Homocysteine complexes. The copper (II) ions were immobilized on a self-assembled monolayer of L-Homocysteine, which was grown on a gold electrode. Cu(II)/L-Homocysteine complexes were characterized by electrochemical methods, such as cyclic voltammetry in phosphate buffer solution (pH=6.2, 0.1M K2HPO4 /KH2PO4). Electrochemistry of Cu2+/Cu+ redox processes were studied at different temperatures (25℃ and 60℃). The system demonstrated a significant transformation of electrochemical signals at 60℃. Specifically, redox-appropriate peaks on the voltammetric graphs have grown enormously and they stayed stable after cooling the system down and leaving it for two days. This change could be attributed to the rearrangement of Copper/L-Homocysteine nanostructure on the gold surface and specific modification of the charge transfer regime. Except for fundamental interest, imitated biological objects containing Cu2+ ions, can be interesting for studying effective, copper sensor/catalysis.

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ანოტაცია/ABSTRACT [en]