Detection of anticancer properties of nivo and bevasizumab by voltametric methods using pencil graphite electrode and investigation of their interaction with dsDNA

In this thesis, an electrochemical biosensing sensor was developed to evaluate the electrochemical behavior of Nivolumab (NIVO) and Bevacizumab (BEVA) drug active ingredients on pencil graphite electrode (PG) and their interactions with DNA. The surface morphology and electrochemical properties of the PG electrode were characterized and analyzed in detail by techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), electro impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrochemical behavior of NIVO and BEVA was investigated by CV and differential pulse voltammetry (DPV). In the measurements using DPV technique, NIVO and BEVA were deposited on the PGE surface in PBS (pH 3.0) containing 0.02 M NaCl. It was determined that NIVO gave a good signal at a voltage value of +0.88 V (vs. Ag/AgCl) and BEVA gave a good signal at a voltage value of +0.90 V (vs. Ag/AgCl). Quantification of NIVO and BEVA was performed with the developed electrochemical biosensing sensor. It was found that NIVO gave a linear response in the concentration range of 0.01-0.07 mg/mL and its LOD value was 2.49 µg/mL and LOQ value was 8.30 µg/mL. BEVA gave a linear response in the concentration range of 0.1-0.7 mg/mL and the LOD value was 0.026 mg/mL and the LOQ value was 0.086 mg/mL. The interactions of NIVO and BEVA molecules with DNA were evaluated based on adenine and guanine signals under the characterized conditions. The interactions were also analyzed by UV-Vis. absorption spectrometry and binding constants were determined. The results show that NIVO and BEVA interact with DNA via intercalation and electrostatic binding. This study provides an important contribution to the electrochemical analysis of NIVO and BEVA and to the understanding of their interactions with DNA. The developed electrochemical biodetection sensor can be used for analytical characterization of antibodies in cancer therapy by providing rapid and sensitive detection of drugs. Furthermore, this study demonstrates the potential of using electrochemical analysis methods in pharmaceutical research and biotechnology.