No abstract

A novel sensing material, MnFe2O4/polyaniline (PANI), was fabricated by doping PANI to MnFe2O4 on a modified glassy carbon electrode (GCE). This sensing material was characterized using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and high‐resolution transmission electron microscopy (HR‐TEM). Using a cyclic voltammetry electrochemical‐sensing method, we tested MnFe2O4/PANI, and an acetaminophen concentration of 0.0625–5 mM was recorded. Furthermore, the sensor responses were 2.05–22.44. The detection limit was 2.23 × 10−7 M. Strong selectivity was observed for MnFe2O4/PANI, which is a possible sensing mechanism.

A urea sensor base on reticulated nickel hydroxide is prepared by hydrothermal way and operated by differential pulse voltammetry method. The reticulated nickel hydroxide has been successfully synthesized by a hydrothermal method and has been characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The Ni(OH)2 sensor exhibits a higher sensor response (S) of 7.1 than NiO and Au sensing materials to 0.05 M urea concentration at 0.62 V. Various concentration of urea from 0.1 mM to 50 mM are performed on Ni(OH)2, and the sensor response are increased from 1.1 to 7.1 by differential pulse voltammetry (DPV) method. The urea detection limit is measured as 0.1 μM in this system. In addition, the Ni(OH)2 sensor exhibited good reproducibility and short term stability, and the response exhibits no obvious changes after 20 days tests. A possible sensing mechanism of Ni(OH)2 urea sensor is presented.