Development of new electrode and electrochemical detection strategies based on nanoparticles

In this study, core-shell structured gold coated superparamagnetic iron nanoparticles were synthesized by using wet chemical methods. The magnetic nanoparticles were modified with chitosan film and glucose oxidase enzyme respectively. Resulting chitosan@gold@iron (chit@Au@Fe3O4) hybrid nanoparticles were immobilized onto the carbon rod electrode and glucose biosensor was prepared. Prepared electrode was characterized by cyclic voltammetry (CV) and scanning electron microscopy (SEM) techniques. Observed amperometric response was measured as a function of concentration of glucose at a potential of 0.6 V vs Ag/AgCl in 0.1 M phosphate-acetate buffer at pH 6.0. The linear range of the calibration curve is from 5 mM to 30 mM, a limit of detection (LOD) of 0.55 mM and limit of quantification (LOQ) of 1.83 mM. The apperent Mishaelis-Menten constant Km is calculated to be 0.59 and the response time is 3 seconds. The results expressed that enzyme electrode modified with chitosan magnetic nanoparticles presents high electroactivity.