A Nonenzymatic Amperometric Glucose Sensor Based on a RuO2/Graphene Sheet Composite Electrode

Abstract

Photoluminescence-based nanomaterial sensors doped with rare-earth elements have a potential for use in sensitive, portable, and low-cost detectors.The oxide with the formula XY 2 ZO 5 has potential for fluorescence applications because of its orthorhombic structure, stable physical and chemical properties, and high thermal stability.In this study, BaY 2 ZnO 5 phosphors with various concentrations of Tm 3+ and urea ions were synthesized at 1200 o C for 8 h in air by the sol-gel method.The characteristics of the phosphor powders were analyzed by field-emission scanning electron microscopy, X-ray diffraction (XRD), and photoluminescence spectroscopy.The diffraction peaks of phosphors with Tm 3+ ion doping concentrations from 0 to 5 mol% and urea additions from 1 to 50 wt% are attributed to the orthorhombic BaY 2 ZnO 5 structure examined by XRD analysis.When the Tm 3+ ion concentration is 2 mol%, the maximum emission intensity of the 1 D 2 → 3 F 4 transition can be obtained, which then decreases with increasing Tm 3+ ion concentration.Concentration quenching occurs when the Tm 3+ ion concentration is above 2 mol%.For BaY 2 ZnO 5 phosphors prepared by doping with Tm 3+ ions and adding urea, excitation with an emission wavelength of 457 nm yields the color tone in the vivid blue region.