Nanobiotechnology / Bionanotechnology / Nanobiology
Mohadese Shahriaripour; Sasan Asiaei
Volume 15, Issue 1 , May 2021, , Pages 87-97
Abstract
Cerium oxide nanoparticles have many applications in medicine. Particle size, shape and concentration of nanoceria are very important for biological applications and biocompatibility. The synthesis method of cerium oxide nanoparticles has an important role in determining nanoceria shape, particle size ...
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Cerium oxide nanoparticles have many applications in medicine. Particle size, shape and concentration of nanoceria are very important for biological applications and biocompatibility. The synthesis method of cerium oxide nanoparticles has an important role in determining nanoceria shape, particle size and concentration. In this project, the effective parameters in determining the concentration, size and size distribution, crystallinity and production of maximum cerium oxide produced from the reactants were simulated and tested. Since in different method, particle size control has become an important challenge, microfluidic chips were used to control particle size. Among the existing methods for nanoparticle synthesis, co-precipitation method was chosen because of its simplicity, cheapness and short time method compared with other methods. Cerium nitrate and sodium hydroxide were used as raw materials to synthesize cerium oxide nanoparticles. Simulations were performed in Comsol and then the results were used for experimental tests, comparison and validation. The nanoparticles were characterized for size and size distribution using x-ray diffraction. The results of this study showed that the use of microfluidic chips is an effective method for controling nanoparticle size. Increasing concentration of sodium hydroxide can complete reaction and have maximum efficiency and decreasing the reactives velocity can reduce the size dispersion, increases the crystallinity and particle size. The yellow precipitate produced, according to Scherer equation, contains cerium oxide nanoparticles with particle size of 1.16±0.1 nm and 85% of crystallinity.
Elham Mollaei; Sasan Asiaei; Mahdi Moghimi; Ali Zadekafi
Volume 12, Issue 3 , November 2018, , Pages 199-210
Abstract
Microfluidic analytical/diagnostic tools, especially microfluidic paper-based analytical devices ( PADs) have attracted considerable attention due to their numerous advantages including their low operational costs, small analyte consumption, and limited required skills for use, and easy disposal/recycling. ...
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Microfluidic analytical/diagnostic tools, especially microfluidic paper-based analytical devices ( PADs) have attracted considerable attention due to their numerous advantages including their low operational costs, small analyte consumption, and limited required skills for use, and easy disposal/recycling. μPADs have been successful in detection of various diseases with no external deriving units. The aim of this study is to develop a micromixer for colorimetric detection of nitrite in saliva using Griess reaction and widening the limit of detection (LOD) by mixing improvement. Micromixers were fabricated using laser cut after a simple design. Five different geometries were examined and compared including straight, curved, zigzag, square wave and hexagonal, by numerical simulation and experimental tests for mixing part in micromixer. Simulations were performed in ANSYS CFX with homogeneous two-phase flow model in a porous media. As the result inclined hexagonal micromixer showed the best performance (in comparison with the straight one) exhibiting 44.24% of improvement which leads to a detection range and LOD of and , respectively. Considering the significant impact of micromixers in microfluidics, the quality of mixing and therefore the accuracy of the devices was improved by simple geometrical modifications.
