This paper employs a spin-coated method to construct conductive polypyrrole (PPy) substrates which present superior properties for controlling the morphological structures and functions of bEnd.3 cells. The PPy substrates with a homogeneous particle size, uniform distribution and proper roughness show enhanced hydrophilic characteristics and improve cell adhesion to the substrates. The changes in the mechanical properties of cells and the responses to the designed substrates and magnetic field are also explored. Due to the synergistic effect between the magnetic field and the conductive PPy substrate, the cells cultured in such an environment exhibit applanate shapes with more branches and enhanced cell viability. In addition, the cells preferentially extend along the magnetic field direction. The mechanical characteristics of cells change significantly under varying magnetic intensity stimulations (5–16 mT). The satisfying effect on cells' morphology and outgrowth is acquired at the magnetic intensities of 9–10 mT and duration of 20 min, compared with other stimulated groups, while retaining cell viability. Moreover, the cells express higher adhesion up to 5.2 nN. The results suggest that the application of the PPy substrates and magnetic field is a promising candidate for the protection of neurovascular units and treatment of neurological diseases.
Ochratoxin A (OTA) can cause various diseases due to its severe toxicity, so its detection in foods is very important. Herein, a ratiometric electrochemical sensor based on molecularly imprinted polymer (RECS-MIP) has been developed for OTA detection. The MIP is prepared by cyclic voltammetry ; during electropolymerization a magnetic field is introduced to regulate the MIP orientation for improving molecular recognition efficiency. A gold nanoparticles , ploy(ionic liquid) and flavin mononucleotide decorated carbon nanotubes - MoS 2 nanosheet composite (Au NPs/PIL-FMNS/CNT-MoS 2 ) is used as substrate to amplify signal and to provide reference signal. The peak current of Au NPs/PIL-FMNS/CNT-MoS 2 decreases with the increase of OTA concentration, while the peak current of OTA oxidation product increases. The ratio of the peak currents changes linearly with OTA concentration variation and is used for OTA quantification. Under the optimized conditions, the linear response range is 0.5–15 μM and the low limit of detection is 14 nM (S/N = 3). The sensor displays high selectivity and reproducibility and has good application potential; it has been applied for the OTA detection in spiked samples and satisfactory results are achieved.
In this work, by taking commercial P25 hydrophilic titanium dioxide (TiO2) as a photocatalyst, the magnetic field effect (MFE) on the photodegradation rate of methyl orange is studied. It is found that a relatively lower magnetic field B = 0.28 T can efficiently enhance the photodegradation efficiency of commercial TiO2 by 24%. However, the photodegradation efficiency of commercial TiO2 will be suppressed slightly by 7% under a magnetic field of 0.5 T. Moreover, such MFE on the photocatalyst is dependent on the settling state of the reaction solution. Additional experiments on the degradation of other pollutants (methylene blue) and with other photocatalysts (g-C3N4) indicate that the MFE is a ubiquitous phenomenon in the photocatalytic degradation process. These observations suggest that the magnetic field can be taken as an efficient strategy to regulate the catalytic process of commercial catalysts and improve the catalytic efficiency.
危险品化学品经营许可证（带存储）