Alginate and alginate-titanium dioxide nanocomposite as electrode materials for anti-myelin basic protein immunosensing

摘要

An electrochemical immunosensing platform for direct protein detection has been developed by immobilization of myelin basic protein (MBP), a multiple sclerosis (MS) auto-antigen, as a model biomarker on an alginate and alginate-titanium dioxide (TiO_2) nanocomposite film modified platinum electrode. Modification steps were evaluated using scanning electron microscopy (SEM). Atomic force microscopy (AFM) was used to investigate the surface topographies of the films. Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) were used as proof for success of nanocomposite material preparation in addition to SEM. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed in determination of the electrode response capability and applicability. The formal potentials and the peak separations showed the electron transfer reaction to be quasireversible. Alginate-MBP and alginate-TiO_2-MBP immunosensors revealed a detection limit of 0.25 ng mL~(-1)and 0.18 ng mL~(-1), respectively. The method employed is both sensitive and practical and the importance and uniqueness of this study lies in the fact that the immunosensor can determine Anti-MBP levels directly from blood samples, without the need for cerebrospinal fluid (CSF).