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J Nanopart Res (2013) 15:1558 DOI 10.1007/s11051-013-1558-9
RESEARCH PAPER
Synthesis of streptavidin-conjugated magnetic nanoparticles for DNA detection
Peijun Gong Zheyang Peng Yao Wang
Ru Qiao Weixing Mao Haisheng Qian
Mengya Zhang Congcong Li Shenyuan Shi
Received: 19 September 2012 / Accepted: 1 March 2013 / Published online: 12 March 2013 Springer Science+Business Media Dordrecht 2013
Abstract In this paper, we report a fabrication of streptavidin-coated magnetic nanoparticles used for DNA detection. Initially, amino-functionalized Fe3O4
nanoparticles with high saturation magnetization are prepared by a photopolymerization method using allylamine as monomer. It is followed by covalent immobilization of streptavidin onto the particle surface via a two-step reaction using glutaraldehyde as coupling agent. Streptavidin-coated magnetic nanoparticles are characterized and further tested for their ability to capture DNA target after binding biotinylated oligonucleotide probes. The results show that the products (*27.2 nm) have a maximum biotin-binding capacity of 0.71 nmol mg-1 when the immobilization reaction is conducted with a mass ratio of streptavidin to magnetic carriers above 0.2 in phosphate buffered saline (pH 7.4) for 24 h. In addition, highly negative f-potential and good magnetic susceptibility of the nanocomposites make them applicable for DNA collection and detection, which is veried by the results from the preliminary application of streptavidin-coated magnetic nanoparticles in DNA detection. Therefore, the magnetic nanoparticles provide a promising approach for rapid collection and detection of gene.
Keywords Magnetic nanoparticles Streptavidin
DNA detection Photopolymerization Saturation
magnetization Zeta potential
Introduction
The rapid collection and detection of disease-related biomolecules from patient samples has received increasing attention in the past few years as people care more about their health. The traditional separation and purication processes are cost-consuming and inefcient to deal with the low-abundance target biomolecules. Nanoparticle-based strategies have been found as an effective and prospective route of developing afnity process with high sensitivity and selectivity in trace level, since various nanoparticles show specially optical, electrical, or magnetic properties as well as high surface-to-volume ratio (Taton et al. 2000; Fan et al. 2005; Tang et al. 2008; Fornara et al. 2008).
Recently, magnetic nanoparticles (MNps), a class of carriers suitable for biomolecule immobilization, have attracted signicant attention due to their properties such as low toxicity, biocompatible surface, facile functionalization, and magnetic controllability (Laurent et al. 2008; Yang et al. 2008;...