Poly (2-hydroxypropylene imines) functionalized magnetic polydopamine nanoparticles for high-efficiency DNA isolation

Abstract A rapid and efficient DNA isolation method without toxic agents and centrifugation is essential. In this study, we synthesized a novel kind of magnetic nanocomposite (Fe3O4@PDA@PHP) readily by coating polydopamine (PDA) and grafting poly (2-hydroxypropylene imines) (PHP) onto the surface of Fe3O4 magnetic nanoparticles for DNA isolation. TEM, FTIR, VSM and XPS characterization results indicated the prepared Fe3O4@PDA@PHP nanocomposite possessed core-shell structure and PHP was successfully grafted onto magnetic polydopamine nanoparticles. The isolation behaviors of Fe3O4@PDA@PHP for DNA were also evaluated taking into factors such as DNA concentration, initial binding solution pH and extraction time. Results showed that pseudo-second-order model and Freundlich isotherm model well fitted the kinetic results and the equilibrium extraction data, respectively. Meanwhile, the resultant magnetic nanocomposite performed excellent isolation properties toward DNA higher than other studied materials at same conditions, and had excellent specificity in presence of some proteins and metal ions. Moreover, Fe3O4@PDA@PHP could retain high isolation capacity after five using-cycles and have high biocompatibility. Therefore, the resultant Fe3O4@PDA@PHP would be a promising device for the isolation of DNA in biological application.