Fabrication of ascorbic sensor acid with Co3O4•Fe2O3 nanosphere materials by electrochemical technique

In this study, the Co3O4 center dot Fe2O3 nanospheres (NSs) was prepared by hydrothermal process in high alkaline environment of pH 10.5. X-ray photoelectron spectroscopy (XPS), field Emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis were performed to characterize the prepared Co3O4 center dot Fe2O3 NSs. The Co3O4 center dot Fe2O3 NSs was subjected to deposit onto a glassy carbon electrode (GCE) of 0.0316 cm(2) surface area with nafion (5% suspension in ethanol) adhesive as thin film to obtain the desire ascorbic acid (AA) sensor. The calibration curve of AA sensor was plotted as current versus concentration of AA, which is a linear from 0.1 nM to 0.01 mM on calibration curve defined as linear dynamic range (LDR). The slope of LDR is used to calculate the sensitivity of sensor by considering the active surface area of electrode and is equal to 15.4367 mu A mu M-1 cm(-2). The limit of detection (LOD; 96.02 +/- 4.80 pM) and the limit of quantification (LOQ; 320.07 +/- 10.0 pM) of AA sensor are calculated. The reproducibility, response time and long-time stability of sensor are exhibited as outstanding. The electrochemical analyzing of real samples, the AA sensor is shown its reliability.