Electrochemical detection of bicalutamide in sepiolite clay sensing platform: Its possible electrooxidation mechanism, determination, and DNA interaction

A carbon paste sensor was modified with sepiolite clay particles (SC/CPE) to quantify the bicalutamide (BICA). BICA's probable oxidation mechanism and the interaction between calf thymus DNA (dsDNA) were investigated (in aqueous medium, pH 4.8) for the first time. Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) were used for the investigation of surface morphology and electrochemical characteristics. The effect of the amount of SC, supporting electrolyte, and pH was optimized. Under optimum conditions, the developed sensor exhibited a linear response between 0.223 and 20.0 mu M. The detection of the limit was found to be 0.069 mu M. The sensor was successfully applied to quantify BICA in biological and pharmaceutical samples. Finally, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) provided new insight into the interaction between BICA and ds-DNA. The kinetic parameters for the free DNA, diffusion coefficient (D), heterogeneous rate constant (ks), and electrode surface concentration (Gamma) were calculated to be 4.22x10-5 cm2 s-1, 0.57 s-1 and 7.67x10-9 mol cm-2, respectively. The (ds-DNA)-BICA complex parameters were 4.56x10-6 cm2 s-1, 0.70 s-1, and 1.61x10-9 mol cm-2. In addition, binding constant (K) and Gibbs free energy change (Delta G degrees) were 6.02x105 M-1 and -32.97 kJ mol-1, respectively. image