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Surface modification of magnetic nanoparticles with alkoxysilanes and their application in magnetic bioseparations.

Bruce, Ian J., Sen, Tapas (2005) Surface modification of magnetic nanoparticles with alkoxysilanes and their application in magnetic bioseparations. Langmuir, 21 (15). pp. 7029-7035. ISSN 0743-7463. E-ISSN 1520-5827. (doi:10.1021/la050553t) (Access to this publication is currently restricted. You may be able to access a copy if URLs are provided) (KAR id:22)

Language: English

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A versatile and inexpensive method for the introduction of amine groups onto the surface of silica-coated magnetite composite nanoparticles has been established based on the condensation of (aminopropyl)triethoxysilane (APTS). The process was observed to be sensitive to a range of variables, and a range of silane surface-modified nanoparticles was synthesized under various reaction conditions, that is, solvent systems [water, tetrahydrofuran (THF), ethanol, or 1:1 mixtures of them], reaction times (from 1 to 24 h), and temperatures (18, 50, and 70 degrees C), with water as the catalyst and silane at either 0.2% or 2% (w/v) in an attempt to optimize the process. The products of the various reactions were characterized in terms of their possession of surface -NH2 groups, morphologies, and properties with respect to DNA binding and elution before being modified with a single-stranded oligonucleotide capture sequence. It was observed that careful manipulation of temperature, time, and solvent conditions was important for optimal silanization of the nanoparticles, and in our experiments best results were obtained when silanization of the particles in suspension involved use of water as the solvent and APTS at 0.2% (w/v) and when the reaction was conducted at room temperature for 5 h and was preceded by ultrasonication of the particle suspension. The materials produced were used in experiments to selectively capture complementary nucleic acid sequences by hybridization after grafting with an oligonucleotide. The efficiency of the oligonucleotide-modified particles in the capture experiments was observed to be directly related to the original density of amine groups present at the surface of the support. The results indicate that surface engineering of the nanoparticles was possible by silanization under defined, optimized conditions. This approach could be extended to the activation of such surfaces and other materials with other functional groups.

Item Type: Article
DOI/Identification number: 10.1021/la050553t
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Susan Davies
Date Deposited: 19 Dec 2007 17:45 UTC
Last Modified: 16 Nov 2021 09:38 UTC
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