Potential of superparamagnetic iron oxide nanoparticles coated with carbon dots as a magnetic nanoadsorbent for DNA isolation

Abstract

In this study, the potential of iron oxide nanoparticles coated with carbon dots (SPION@CDs) as a magnetic nano-adsorbent was studied for DNA bioseparation. The current research reports the core-shell structure of SPION@CDs synthesized using a one-step solvothermal method. The synthesized pH-sensitive SPION@CDs nanohybrid electrostatically isolated DNA at pH= 2 and released it at pH= 8, with a maximum adsorption capacity of 125.12 µg/mg. The method was described by the charge switch of functional groups on the magnetic particle’s surface. The Freundlich isotherm model with pseudo-second-order kinetics offered the best fit with R2 = 0.99. The (3-(4,5-dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay results demonstrated that the cell viability of Human foreskin fibroblasts (HFF) stayed above 90% after 24 h at a high concentration (500 µg/mL), showing high biocompatibility and low toxicity of SPION@CDs, which could be a potential candidate for biological applications. The binding ability of the nanohybrids to DNA were determined by electrophoresis and proved that the separation process was successful and the eluted DNA is suitable for subsequent biological processes. The results revealed that the novel nanohybrid (SPION@CDs) is an effective adsorbent for DNA separation due to its low cost, ease of fabrication, high extraction capacity, reusability, and protection of the DNA structure.