Synthesis And Characterization Of Thermoresponsive Poly(N-Isoproylacrylamide)-DNA Bioconjugates
Loading...
Date
2012-07
Authors
Ooi, Wei Yang
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Bioconjugates (PNIPAAm−graft−DNA) of poly(N-isopropylacrylamide) (PNIPAAm) grafted with single-stranded (ss) DNA were synthesized via radical copolymerization. The bioconjugates self-assembled above its lower critical solution temperature (LCST) in aqueous solution to form micelle-like colloidal nanoparticles. When the ssDNA of the nanoparticle hybridizes with complementary DNA, the particles aggregate above a certain threshold of salt concentration with drastically increased turbidity in solution. The unique properties of the bioconjugates have so far found applications in biosensor and purification. However, the internal structures of the nanoparticles and the non-crosslinking aggregation mechanism have not been fully clarified yet. Moreover, the structures of the graft bioconjugates are less defined due to the uncontrolled synthesis method developed so far. In this study, advanced characterization using mainly small-angle X-ray scattering (SAXS) has provided a detailed structural insight of the PNIPAAm−graft−DNA colloidal nanoparticles, leading to a better understanding of the interparticle non-crosslinking aggregation mechanism. The SAXS analyses have provided that the nanoparticle consists of a core formed by hydrophobic PNIPAAm segments, surrounded by a coronal layer of DNA component in a brush-like structure.
Description
Keywords
Synthesis and characterization of thermoresponsive , poly(n-isoproylacrylamide)-DNA bioconjugates