Henan University of Technology

About: Henan University of Technology is a education organization based out in Zhengzhou, China. It is known for research contribution in the topics: Catalysis & Chemistry. The organization has 7648 authors who have published 6503 publications receiving 73067 citations. The organization is also known as: Hénán Gōngyè Dàxué.

Aptamer based voltammetric patulin assay based on the use of ZnO nanorods.

Abstract: The authors describe an aptamer based assay for the mycotoxin patulin (PAT). A gold electrode was modified with a composite made from ZnO nanorods (ZnO-NRs) and chitosan. The ZnO-NRs was prepared by reaction with ammonia and subsequent hydrothermal growth. Its properties were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Subsequently, thiol-modified aptamers were self-assembled on AuNPs that had been electrodeposited on the surface of the modified electrode. The presence of ZnO-NRs on the electrode increases the loading with AuNPs and aptamers. It also warrants a relatively stable microenvironment for the aptamers. In the presence of PAT, it will form a complex with the aptamer on the electrode surface. This hinders electron transfer from the electrode to the redox probe hexacyanoferrate and results in reduced current, which is typically measured at 0.176 V (vs. Ag/AgCl). The concentration of PAT can be calculated from the differences in the peak current before and after incubation with PAT. The assay has a linear response in the 50 ng·mL−1 to 0.5 pg·mL−1 PAT concentration range and a 0.27 pg·mL−1 lower detection limit. The sensor is specific, reproducible, repeatable, and long-term stable. It was successfully applied to the determination of PAT in spiked juice samples.

Voltammetric determination of theophylline at a Nafion/multi-wall carbon nanotubes composite film-modified glassy carbon electrode

Abstract: A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and applied to the sensitive and convenient determination of theophylline (TP). Multi-wall carbon nanotubes (MWNTs) were easily dispersed homogeneously into 0.1% Nafion methanol solution by sonication. Appropriate amount of Nafion/MWNTs suspension was coated on a glassy carbon electrode. After evaporating methanol, a Nafion/MWNTs composite film-modified electrode was achieved. TP could effectively accumulate at Nafion/MWNTs composite film-modified electrode and cause a sensitive anodic peak at around 1180 mV (vs SCE) in 0.01 mol/L H2SO4 medium (pH 1.8). In contrast with the bare glassy carbon electrode, Nafion film-modified electrode, Nafion/MWNTs film-modified electrode could remarkably increase the anodic peak current and decreased the overpotential of TP oxidation. Under the optimized conditions, the anodic peak current was proportional to TP concentration in the range of 8.0 × 10−8–6.0×10−5 mol/L, with a detection limit of 2.0 × 10−8 mol/L. This newly developed method was used to determine TP in drug samples with good percentage of recoveries.