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DyF3/Bi2O3nanowires with orthorhombic DyF3and triclinic Bi2O3phases were synthesized via a facile hydrothermal route using sodium dodecyl sulfate (SDS). The composite nanowires were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. The obtained composite nanowires have the length of longer than 10 μm and diameter of about 20–100 nm. X-ray photoelectron spectroscopy confirms the composition of Dy, F, Bi and O in the composite nanowires. The formation process of the DyF3/Bi2O3nanowires was analyzed based on the morphological and structural evolution of the products from different growth conditions. The cyclic voltammetry (CV) measurement demonstrates good electro-catalytic activity of the composite nanowires towards L-cysteine. Two pairs of CV peaks at +0.08 V, −0.43 V and −0.48 V, −0.78 V, respectively are observed at the DyF3/Bi2O3nanowires modified glassy carbon electrode. DyF3/Bi2O3nanowires modified glassy carbon electrode detects L-cysteine linearly over a concentration range from 0.001 to 2 mM with a detection limit of 0.25 μM. Moreover, the results show good selectivity, reproducibility and stability of the DyF3/Bi2O3nanowires as a promising candidate for L-cysteine determination.

Bi5-xNax/2Cex/2Ti3FeO15(BNTF-100x, x?=?0, 0·05, 0·10, 0·20, 0·30, 0·40 and 0·60) ceramics were prepared via solid state sintering process. With xincreasing, the resistivity increases at first and then decreases. The lower the concentration of oxygen vacancies, caused by more (Na,Ce) dopant adding, the less the deep trap energies in the band gap for the activated electrons to be mobile. For the samples containing high concentration of oxygen vacancies, the conductivities are higher when they are annealed in the air and oxygen than that in the vacuum. On the contrary, for the samples containing low concentration of oxygen vacancies, the conductivities of the samples in different annealing conditions behave quite the same way. Most (Na,Ce) doped Bi5Ti3FeO15ceramics exhibit intrinsic conduction at high temperatures with corresponding activation energies of 1·1–1·6 eV, while the extrinsic conduction has a close relationship with the concentration of oxygen vacancies and the activation ability of electrons.

Zinc bismuthate nanorods with single crystalline cubic ZnBi38O58phase have been synthesized by a simple hydrothermal process using zinc acetate and sodium bismuthate without any additives. Electron microscopy images show the nanorods have the length and diameter of 2–10 μm and 40–250 nm, respectively. The growth of the zinc bismuthate nanorods has been proposed as a nucleation and crystalline growth process based on the structure and morphology of the products obtained from different hydrothermal conditions. Zinc bismuthate nanorods modified glassy carbon electrode (GCE) has been prepared and used for the electrochemical determination of L-cysteine. A pair of semi-reversible redox peaks located at −0.07 V and −0.52 V are observed at the nanorods modified GCE in KCl solution and the electrode process is diffusion controlled. The intensities of the CV peaks increase obviously with increasing L-cysteine concentration and scan rate. There is a linear relationship between the peak current and concentration of 0.0001–2 mM. The detection limit is 0.074 μM (based on the signal-to-noise ratio of 3) with a correlation coefficient of 0.996. The nanorods modified GCE shows good stability and reproducibility.

The electrochemical responses of ascorbic acid have been investigated by cyclic voltammetry on the CuGeO3/20wt% polyaniline nanowire modified glassy carbon electrode at room temperature. The results show that the modified electrode exhibits good analytical performance for the electrochemical detection of ascorbic acid in neutral solution. The intensities of the anodic cyclic voltammogram (CV) peaks increase linearly with the increase of the ascorbic acid concentration from 0.001 to 2 mM and scan rate from 25 to 200 mVs−1. CuGeO3/20wt% polyaniline nanowire modified glassy carbon electrode exhibits good reproducibility, stability, low detection limit of 0.61 μM and 0.26 μM for cvp1 and cvp2, respectively, which is better than those at other modified electrodes.

Copper germanate (CuGeO3) nanowires are used as the modified materials of glassy carbon electrode to investigate the electrochemical behavior of ascorbic acid. The results show that CuGeO3nanowire modified glassy carbon electrode exhibits good performance for the electrochemical detection of ascorbic acid in neutral solution. The intensities of two anodic peaks vary linearly with the concentration of ascorbic acid in the range of 0.01–5 mM and the detection limit is 24 μM and 8.6 μM, respectively at a signal-to-noise ratio of 3, which makes it possible to sensitive detection of ascorbic acid using the CuGeO3nanowire modified glassy carbon electrode. The CuGeO3nanowire modified electrode exhibits good reproducibility and stability. The good analytical performance makes that the CuGeO3nanowires can be used as the electrode modified materials for a wide range of potential application for detecting ascorbic acid.