Superparamagnetic Nanocomposite of Magnetite-Chitosan Using Oleic Acid as Anti Agglomeration and Glutaraldehyde as Crosslinkage Agent

Abstract

In this research magnetite was synthesized by coprecipitation method, in which solution of NH4OH was added into the solution containing a mixture of Fe2+/Fe3+ (molar ratio 1:2) until pH 11 under strong ultrasonic agitation for 30 min. The black sediment of magnetite was filtered, washed and dried. The product was then modified by using oleic acid to prevent agglomeration. Chitosan was prepared by deacetilization of chitin, whereas chitin was extracted from shrimp shell. In the synthesis of nanocomposite, 0.5 g of chitosan and 1.5 g of oleic acid modified magnetite were introduced into 100 mL of 2% acetic acid solution, followed by sonication treatment for 10 min and magnetic stirring for 20 min. In order to perform the cross-linkage reaction, solution of 2% glutaraldehyde was added into the mixture at temperature of 40 °C for 3 h. The composite was collected by magnetic separation, followed by washing with distilled water and ethanol in a row. The product was dried and characterized by XRD, FTIR, TEM and VSM methods. The result showed that the composite had good crystal structure with a cubic inverse spinel structure, monodisperse and quasi sphere in shape with diameter of 20–25 nm. It had high saturation magnetization (43.4 emu/g) and superparamagnetic property.

Rapid purification and enrichment of viral particles using self-propelled micromotors

“…Moreover, the bands of CMCS@SA at 1415 cm −1 and 1625 cm −1 were attributed to the –OH bending of the COOH group and the signal overlap of the newly formed –NH + 3 asymmetric stretching of CMCS and the –CO– of SA after moving approximately 15 cm −1 . 40…”

“…Moreover, the bands of CMCS@SA at 1415 cm −1 and 1625 cm −1 were attributed to the -OH bending of the COOH group and the signal overlap of the newly formed -NH + 3 asymmetric stretching of CMCS and the -CvOof SA after moving approximately 15 cm −1 . 40 Next, we characterized the ability of the anti-SP-CSFA motors to capture viral particles by incubating them with target virus samples. Here, a pseudovirus ( pseudovirus-2019-nCOV) was applied as a coronavirus mimic since the shell of a pseudovirus contains spike proteins, which can be identified by anti-SP-CSFA, while the core (RNA sequence of Luciferase) can be quantified by RT-PCR.…”

Preparation and Characterization of Magnetic Material/Chitosan Composite Modified with Glycidyl-Trimethylammonium Chloride

“…The absorption peaks of functional groups of GTMAC [11] include C-O-C epoxides (861, 928, and 961 cm −1 ), C-H from CH 3 (1,475 cm −1 ), and N-H (3,356 cm −1 ). Fe-O was observed at the wavenumber of 680 cm −1 [47]. All composites have the three characters of MM, chitosan, and GTMAC, except for the MM/chi(0)/GTMAC.…”

Magnetic Mesoporous Silica Composite for Enhanced Preconcentration of Selected Organophosphorus Pesticides in Fruits

“…In recent years, magnetic solid phase extraction (MSPE) a pioneering technique for sample preparation as well as performed a great interest in order to improve the stability, sensitivity, compatibility, and good extraction efficiency. It is a new mode of SPE based on the adoption of magnetic or magnetizable adsorbents which can be readily isolated from the sample matrix by an external magnet without any filtration or centrifugation [21][22]. Notably, magnetic sorbents are uniformly dispersed into suspension by vortexing or shaking to enhance the interfacial area between sorbent and analytes, which give high extraction efficiency in a short time [20,22].…”

“…It is a new mode of SPE based on the adoption of magnetic or magnetizable adsorbents which can be readily isolated from the sample matrix by an external magnet without any filtration or centrifugation [21][22]. Notably, magnetic sorbents are uniformly dispersed into suspension by vortexing or shaking to enhance the interfacial area between sorbent and analytes, which give high extraction efficiency in a short time [20,22].…”