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Your search keyword '"Asadpour Zeynali, Karim"' showing total 223 results
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223 results on '"Asadpour Zeynali, Karim"'

32. Non-invasive and probeless rapid in-vitro monitoring and quantification of HUVECs counts based on FFT impedimetery.

Author

Mirzazadeh, Jalil, Majidi, Mir Reza, Norouzi, Parviz, Faridi-Majidi, Reza, and Asadpour-Zeynali, Karim

Subjects
ELECTRIC batteries, ELECTRIC admittance measurement, FAST Fourier transforms, PLATINUM electrodes, UMBILICAL veins
Abstract

Introduction: The endothelial cells derived from the human vein cord (HUVECs) are used as in-vitro models for studying cellular and molecular pathophysiology, drug and hormones transport mechanisms, or pathways. In these studies, the proliferation and quantity of cells are important features that should be monitored and assessed regularly. So rapid, easy, noninvasive, and inexpensive methods are favorable for this purpose. Methods: In this work, a novel method based on fast Fourier transform square-wave voltammetry (FFTSWV) combined with a 3D printed electrochemical cell including two inserted platinum electrodes was developed for non-invasive and probeless rapid in-vitro monitoring and quantification of human umbilical vein endothelial cells (HUVECs). The electrochemical cell configuration, along with inverted microscope images, provided the capability of easy use, online in-vitro monitoring, and quantification of the cells during proliferation. Results: HUVECs were cultured and proliferated at defined experimental conditions, and standard cell counts in the initial range of 12 500 to 175 000 were prepared and calibrated by using a hemocytometer (Neubauer chamber) counting for electrochemical measurements. The optimum condition, for FFTSWV at a frequency of 100 Hz and 5 mV amplitude, were found to be a safe electrochemical measurement in the cell culture medium. In each run, the impedance or admittance measurement was measured in a 5 seconds time window. The total measurements were fulfilled at 5, 24, and 48 hours after the seeding of the cells, respectively. The recorded microscopic images before every electrochemical assay showed the conformity of morphology and objective counts of cells in every plate well. The proposed electrochemical method showed dynamic linearity in the range of 12 500-265 000 HUVECs 48 hours after the seeding of cells. Conclusion: The proposed electrochemical method can be used as a simple, fast, and noninvasive technique for tracing and monitoring of HUVECs population in in-vitro studies. This method is highly cheap in comparison with other traditional tools. The introduced configuration has the versatility to develop electrodes for the study of various cells and the application of other electrochemical designations. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Application of Co9S8@MoS2 core–shell/rGO nanocomposite as a novel electrocatalyst in preparation of sensor for the determination of metronidazole.

Author

Lotfi, Nasrin, Majidi, Mir Reza, and Asadpour-Zeynali, Karim

Subjects
CARBON electrodes, FOURIER transform infrared spectroscopy, METRONIDAZOLE, GRAPHENE oxide, VOLTAMMETRY technique, NANOCOMPOSITE materials, ELECTROCATALYSTS, ELECTROLYTIC reduction
Abstract

This study is the first report on the application of Co9S8@MoS2 core–shell nanoparticles decorated with reduced graphene oxide in the fabrication of an electrochemical sensor. This sensor exhibited great performance in the determination of metronidazole in blood plasma and tablet samples. These nanoparticles were synthesized via a facile and simple preparation method. First, Graphene oxide was synthesized via the Hummer method, and then Co9S8@MoS2 core–shell nanoparticles were synthesized on the surface and edges of the reduced graphene oxide. In this way, the glassy carbon electrode was modified with Co9S8@MoS2/Reduced graphene oxide nanoparticles. The nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy. The performance of the prepared sensor was studied by hydrodynamic amperometry and cyclic voltammetry techniques. A significant rise in the peak current and a considerable reduction in the overpotential of metronidazole were identified in the prepared sensor compared to the bare glassy carbon electrode. Under optimized conditions, two linear ranges of 0.5–35.0 μM and 35–180 μM and a limit of detection of 0.38 µM were obtained for metronidazole through the hydrodynamic amperometry technique using the proposed sensor. The Co9S8@MoS2/Reduced graphene oxide sensor demonstrated good reproducibility, fast response, and a large specific area. [ABSTRACT FROM AUTHOR]

Published
2024
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