Magnetic extraction and purification of DNA from whole human blood using a γ-Fe2O3@Chitosan@Polyaniline hybrid nanocomposite

[Display omitted] •Use of the γ-Fe2O3@Chi@Pani MNC as an adsorbent dispenses the need for toxic solvents or centrifugal steps.•The combined presence of chitosan and polyaniline leads to an increase in the DNA adsorption rate.•The DNA extracted using γ-Fe2O3@Chi@Pani MNC has the adequate quality for use in molecular biology protocols. We examined the properties of the nanocomposite γ-Fe2O3@Chi@Pani as an adsorbent of deoxyribonucleic acid (DNA). As a model system, we used an aqueous solution of salmon sperm DNA, whose decreasing concentration was followed by monitoring the 260 nm UV–vis absorption. After adjusting the data collected to a Langmuir isotherm curve, we estimated the adsorption capacity (qe) of the nanocomposite as 49.5 mg/g. We also observed that the kinetic model of the DNA capture presents a mixed character, with both chemical mechanisms and intraparticle diffusion processes involved. When the MNC was used to extract the DNA from complex samples (human blood), a capture rate of 80 ng/μL was achieved, with the collected fraction exhibiting good quality, as evaluated by PCR analysis and electrophoresis assays. These results suggest that the γ-Fe2O3@Chi@Pani nanocomposite is a promising adsorbent for use in protocols for purification of DNA from complex samples.