Ultra-sensitive xanthine sensor development based on wet-chemically prepared Co/ZnO nanoparticles

Co-doped ZnO nanoparticles (Co/ZnO NPs) were prepared by a facile wet-chemical method using reducing agents in alkaline medium. The Co/ZnO NPs were characterized by Ultra-Violet/visible (UV/vis) spectroscopy, Fourier-Transform Infra-Red (FT-IR) spectroscopy, field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The Co/ZnO NPs were deposited on flat glassy carbon electrode (GCE) with conducting nafion binders to result in a sensor that has a fast response towards selective xanthine. Characteristics including higher sensitivity, lower-detection limit, better reliability, good reproducibility, ease of integration, long-term stability, highly selective, and enhanced electrochemical performances were investigated in details. The calibration plot is linear (r(2): 0.9924) over concentration range (5.0 nM-0.05 mM). The sensitivity and detection limit were calculated as similar to 53.1 mu Acm(-2) mu M-1 and 0.1788 +/- 0.002 nM (at a signal-to-noise-ratio, SNR of 3) respectively. Finally, the efficiency of the proposed chemi-sensors could applied and effectively utilized for the detection of xanthine compound with acceptable and reasonable results.