Impedimetric Detection of Amyloid Beta (1–42) on Curcumin-Copper Complex Electropolymerized Graphite Electrode

In the study, curcumin (Cur) electropolymerization on the surface of disposable pencil graphite electrode (PGE) was carried out using cyclic voltammetry (CV) technique. The interaction of curcumin electropolymerized on PGE surface with aluminum (Al), nickel (Ni), and copper (Cu) metals was investigated using differential pulse voltammetry (DPV) technique. It was observed that the highest interaction between curcumin–metal complexes occurred in the presence of Cu (II). Electrochemical characterization of poly (Cur)-Cu (II)/PGE was carried out by electrochemical impedance spectroscopy (EIS) and CV measurements. The detection of interaction of curcumin with Cu (II) in different concentration ratios was investigated by EIS technique. Aβ (1–42) peptide is known to play a significant role in the pathogenesis of Alzheimer's disease (AD). The immobilization of Aβ (1–42) on the PGE surface at different temperatures and its various concentration was optimized and accordingly, the impedimetric results were recorded. The limit of detection for the analysis of Aβ (1–42) on the PGE surface was calculated over a linear concentration range of 1–20 µM and found to be 0.99 µM. The immobilization of Aβ (1–42) peptide onto the electrode surface was performed by using poly (Cur)/PGE, Cu (II)/PGE, and poly (Cur)-Cu (II)/PGE as well as PGE. According to these results, the highest interaction was obtained in the presence of Aβ (1–42) peptide onto the surface of poly (Cur)-Cu (II)/PGE. The biointeraction of Aβ (1–42) peptide with curcumin-Cu (II) complex offers promising opportunities for the development of different approaches and potential drugs for the diagnosis of AD. The determination of the biointeraction of Aβ (1–42) peptide with curcumin-Cu(II) complex based on the impedimetric method holds promise for the development of different approaches to the diagnosis and new molecules for the treatment of AD.