Magneto-separation of genomic deoxyribose nucleic acid using pH responsive Fe3O4@silica@chitosan nanoparticles in biological samples

Magnetic adsorption technology of polymer functionalized superparamagnetic nanoparticles is showing great potential in biomedical applications because of their facile on and off state of magnetization. Highly magnetized superparamagnetic nanoparticle based magnetic adsorption technology was employed for the purification of DNA. The core-shell Fe3O4 nanoparticles were synthesized by alkaline precipitation and subsequently coated with silica by sol-gel method. Further, silica coated Fe3O4 nanoparticles functionalized with chitosan were used as an adsorbent for DNA. The surface adsorption of DNA onto the modified nanoparticles was optimized as a function of pH, time and temperature. The adsorption efficiency of Fe3O4@silica@chitosan nanoparticles was examined by UV visible spectroscopy. Fe3O4@silica@chitosan nanoparticles with the high adsorption efficiency of similar to 88% and a high elution efficiency of similar to 98% were employed for DNA isolation from human saliva. Agarose gel electrophoresis was used to validate the quality and quantity of DNA isolated from human saliva. Square wave voltammetry was carried out for monitoring the quantitative information about DNA fragment concentration. This method has potential application in the field of bioelectrochemical analysis. The isolation results of genomic DNA from saliva indicated that the Fe3O4@silica@chitosan nanoparticles have outstanding advantages in operation, selectivity, and capacity over the present existing isolation protocols (phenol-chloroform extraction). Furthermore, it opens up new opportunities in detection and isolation of nucleic acid.