In Situ Immobilized Sesamol-Quinone/Carbon Nanoblack-BasedElectrochemical Redox Platform for Efficient Bioelectrocatalytic and Immunosensor Applications

摘要

Most of the common redox mediators such as organic dyes and cyanide ligand-associated metal complex systems that have been used for various electrochemical applications are hazardous nature. Sesamol, a vital nutrient that exists in natural products like sesame seeds and oil, shows several therapeutic benefits including anticancer, antidiabetic, cardiovascular protective properties, etc. Herein, we introduce a new electrochemical redox platform based on a sesamol derivative, sesamol-quinone (Ses-Qn; oxidized sesamol), prepared by the in situ electrochemical oxidation method on a carbon nanoblack chemically modified glassy carbon electrode surface (GCE/CB@Ses-Qn) in pH 7 phosphate buffer solution, for nontoxic and sustainable electrochemical, electroanalytical, and bioelectroanalytical applications. The new Ses-Qn-modified electrode showed a well-defined redox peak at E^o = 0.1 V vs Ag/AgCl without any surface-fouling behavior. Following three representative applications were demonstrated with this new redox system: (i) simple and quick estimation of sesamol content in the natural herbal products by electrochemical oxidation on GCE/CBfollowed by analyzing the oxidation current signal. (ii) Utilizationof the GCE/CB@Ses-Qn as a transducer, bioelectrocatalytic reduction,and sensing of H2O2 after absorbing the horseradishperoxidase (HRP)-based enzymatic system on the underlying surface.The biosensor showed a highly selective H2O2 signal with current sensitivity and detection limit values 0.1303μA μM^–1 and 990 nM, respectively, withtolerable interference from the common biochemicals like dissolvedoxygen, cysteine, ascorbic acid, glucose, xanthine, hypoxanthine,uric acid, and hydrazine. (iii) Electrochemical immunosensing of whitespot syndrome virus by sequentially modifying primary antibody, antigen,secondary antibody (HRP-linked), and bovine serum albumin on the redoxelectrode, followed by selective bioelectrochemical detection of H2O2.