Shengjiao Yu

An electrochemical sensor for honokiol based on a glassy carbon electrode modified with MoS2/graphene nanohybrid film

A novel honokiol electrochemical sensor based on a MoS2/graphene nanohybrid has been introduced in this work. The hybrid was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical behavior of honokiol on the MoS2/graphene modified glassy carbon electrode was investigated in a phosphate buffer solution of pH 5.5 by cyclic voltammetry and differential pulse voltammetry. Compared with bare glassy carbon electrode, the proposed electrode showed improved analytical performance characteristics in the catalytic redox of honokiol. Under the optimal conditions, the modified electrode showed a linear voltammetric response to the honokiol in a concentration range from 1.0 × 10−9 to 2.5 × 10−6 mol L−1, and the detection limit (S/N = 3) was estimated to be 6.2 × 10−10 mol L−1. Moreover, the sensor also exhibited good reproducibility and stability, and could be used for the detection of honokiol in pharmaceutical samples.

Enhanced photoelectric performance of Cu2−xSe nanostructure by doping with In3+

In3+ doped Cu2−xSe nanostructures have been successfully synthesized on a flexible carboxyl functionalized multi-walled carbon nanotubes/polyimide (COOH-MWCNTs/PI) membrane substrate by an electrochemical codeposition method. In this work, the focus was on the effect of different In3+ doping concentrations upon the morphological, structural, optical and photoelectrical properties of Cu2−xSe. Two different kinds of nanostructures, nanoflowers and nanolayers, were obtained. The crystallinity of Cu2−xSe was improved by doping with In3+. The atomic ratio of Cu, Se in Cu2−xSe nanolayers is about 1.85 : 1.00, and the atomic % of In is 1.32, confirming the presence of indium. The optical absorption intensity increased with an increase in the doping content of indium ions. However, In3+ had no effect upon the band gap and absorption edge. The effect of In3+ dopant on the photoelectric properties was investigated by photocurrent–time and current–voltage (I–V) measurements, which demonstrated that the photoelectric properties of Cu2−xSe were improved by doping with In3+. This result is significant for the fabrication of optoelectronic nanomaterials and photodetectors based on In3+-doped Cu2−xSe nanoflowers and nanolayers.

An In-ZnO nanosheet–modified carbon nanotube–polyimide film sensor for catechol detection

We report the fabrication of a catechol (CC) sensor based on an In-modified ZnO/carbon nanotube–polyimide (In-ZnO/PI–CNT) film by using a simple electrochemical method. The decoration of In nanoparticles and control of the size and morphology of In nanostructures provide a great opportunity to improve the catalytic activity of ZnO nanosheets. In nanoparticles supported on the ZnO nanosheets exhibit relatively large surface areas and can enhance the electron transfer. An In-ZnO/PI–CNT film is more active for the catalysis of CC than the ZnO/PI–CNT film and the In(3.79%)-ZnO/PI–CNT film shows the best catalytic activity. The In(3.79%)-ZnO/PI–CNT film sensor exhibits a wide linear range, good long-term stability and reproducibility, and performs well for detection of CC in real water samples. The In(3.79%)-ZnO/PI–CNT film holds great potential for the fabrication of efficient sensors.