Contributions of Phosphate to DNA Adsorption/Desorption Behaviors on Aminosilane-Modified Magnetic Nanoparticles

Langmuir ◽  
2009 ◽  
Vol 25 (5) ◽  
pp. 2956-2961 ◽  
Author(s):  
Tsuyoshi Tanaka ◽  
Ririko Sakai ◽  
Ryosuke Kobayashi ◽  
Keiichi Hatakeyama ◽  
Tadashi Matsunaga
2013 ◽  
Vol 284-287 ◽  
pp. 271-275
Author(s):  
Chi Hsien Liu ◽  
Yi Fan Hsien

Cationic magnetic nanoparticles are prepared by covalently binding spermidine and polyethylenimine onto the surface of nanoparticles via a glutaraldehyde coupling method. Nanoparticles modified by spermidine or polyethylenimine were characterized using Fourier-transformed infrared spectra, transmission electron microscopy and scanning electron microscopy. In this study, cationic magnetic nanoparticles were prepared by covalently conjugating cationic ligands onto the surface of nanoparticles. The plasmid DNA adsorption by the surface-modified magnetic nanoparticles was analyzed by Freundlich, Temkin, and Langmuir models. The maximal adsorption capacities in Langmuir model for polyethylenimine- and spermidine- modified nanoparticles are 341 and 116 μg/mg, respectively. Overall, the results demonstrated that the polyethylenimine-modified magnetic nanoparticles has the potential for purification of plasmid.


NANO ◽  
2019 ◽  
Vol 14 (05) ◽  
pp. 1950065
Author(s):  
Yongsheng Jia ◽  
Enze Li ◽  
Zhiping Du ◽  
Jianfeng Li ◽  
Fangqin Cheng

Bisphenol A is not only one of the frequent contaminants of industrial wastewater, but also one of the main ingredients in polycarbonate and epoxy resins. This study synthesizes a pH-triggered Fe3O4@mSiO2@DPDES adsorbent for recycling Bisphenol A through adsorption–desorption process. Due to the strong [Formula: see text]–[Formula: see text] interaction between the phenyl groups in diphenyldiethoxysilane modified magnetic nanoparticles (MNPs) and Bisphenol A, absorbance reached 120.17[Formula: see text]mg/g at pH 7, allowing the bisphenol A adsorbed to Fe3O4@mSiO2@DPDES to be trivially separated from aqueous solutions with a magnet. Desorption of the adsorbed bisphenol A in aqueous solution occurred at pH 2, allowing an impressive 95% recovery rate. The durability of the Fe3O4@mSiO2@DPDES adsorbent was tested by repeated separation of bisphenol A from an aqueous solution, with the recovery efficiency remaining greater than 85% after five cycles.


Langmuir ◽  
2011 ◽  
Vol 27 (6) ◽  
pp. 3106-3112 ◽  
Author(s):  
Fei Xu ◽  
James H. Geiger ◽  
Gregory L. Baker ◽  
Merlin L. Bruening

2021 ◽  
Vol 22 (12) ◽  
pp. 6571
Author(s):  
Yu-Chen Liu ◽  
Katragunta Kumar ◽  
Cheng-Hsiu Wu ◽  
Kai-Chih Chang ◽  
Cheng-Kang Chiang ◽  
...  

A nucleic acid aptamer that specifically recognizes methicillin-resistant Staphylococcus aureus (MRSA) has been immobilized on magnetic nanoparticles to capture the target bacteria prior to mass spectrometry analysis. After the MRSA species were captured, they were further eluted from the nanoparticles and identified using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The combination of aptamer-based capture/enrichment and MS analysis of microorganisms took advantage of the selectivity of both techniques and should enhance the accuracy of MRSA identification. The capture and elution efficiencies for MRSA were optimized by examining factors such as incubation time, temperature, and elution solvents. The aptamer-modified magnetic nanoparticles showed a capture rate of more than 90% under the optimized condition, whereas the capture rates were less than 11% for non-target bacteria. The as-prepared nanoparticles exhibited only a 5% decrease in the capture rate and a 9% decrease in the elution rate after 10 successive cycles of utilization. Most importantly, the aptamer-modified nanoparticles revealed an excellent selectivity towards MRSA in bacterial mixtures. The capture of MRSA at a concentration of 102 CFU/mL remained at a good percentage of 82% even when the other two species were at 104 times higher concentration (106 CFU/mL). Further, the eluted MRSA bacteria were successfully identified using MALDI mass spectrometry.


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