Cai-Feng Ding

Disposable biosensor and biocatalysis of horseradish peroxidase based on sodium alginate film and room temperature ionic liquid

Composite material based on room temperature ionic liquid (RTIL) N-butylpyridinium hexafluorophosphate (BPPF(6)), sodium alginate (SA), and graphite was used to construct a novel horseradish peroxidase (HRP) biosensor for the determination of H(2)O(2). The morphology of the as-prepared biosensor was characterized by scanning electron microscopy (SEM). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the process of the performance of the biosensor. Parameters affecting the performance of the biosensor, including the concentrations of o-aminophenol (OAP) and HRP and the pH value of substrate solution, were optimized. Under the optimized experimental conditions, H(2)O(2) could be detected in a linear calibration range of 1.0 to 6.0 microM with a correlation coefficient of 0.9847 (n=7) and a detection limit of 0.5 microM at a signal/noise ratio of 3. The prepared biosensor not only had economic and disposable property but also showed good detection precision, bioactivity, storage stability, and reproducibility.

Electrochemical cytosensor based on gold nanoparticles for the determination of carbohydrate on cell surface.

An electrochemical cytosensor was designed based on the specific recognition of mannosyl on a cell surface to concanavalin A (ConA) and the signal amplification of gold nanoparticles (NPs). By sandwiching a cancer cell between a gold electrode modified with ConA and the gold NPs with ConA and 6-ferrocenylhexanethiol (Fc), the electrochemical cytosensor was established. The cell number and the amount of cell surface mannose moieties were quantified by cyclic voltammetry (CV) analysis of the Fc loaded on the surface of the gold NPs. Since a single gold NP could be loaded with hundreds of Fc, a significant amplification for the detection of target cell was obtained. By using K562 leukemic cells (K562 cells) as a model, the electrochemical response was proportional to the cell concentration in the range from 1.0×10(2) to 1.0×10(7) cells mL(-1), showing very high sensitivity. The signal amplification could be further used to evaluate the cell surface mannose moieties, and the amount of mannose moieties on a single living K562 cell was detected to correspond to 4.7×10(9) molecules of free mannose. This strategy presents a promising platform in a highly sensitive cytosensor and convenient estimation of cell surface carbohydrate.

Crystal structure and thermal chemical properties of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane

The crystal structure of 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorane has been determined by single crystal X-ray diffraction method. The crystal belongs to triclinic system, space group P-1 with unit cell constants a = 11.2877(9) Å, b = 11.9539(9) Å, c = 12.2365(9) Å, α = 97.2580(10)°, β = 116.2850(10)°, γ = 106.3710(10)°, V = 1358.48(18) Å3, Z = 2, Dc = 1.234 g/cm3, μ = 0.079 mm−1, F(000) = 536, R and w(R) are 0.0718 and 0.2055, respectively, for 5239 unique reflections with 3745 observed reflections (I > 2σ(I)).