Fabrication of temperature and pH sensitive decorated magnetic nanoparticles as effective biosensors for targeted delivery of acyclovir anti-cancer drug

Magnetic nanoparticles are promising materials for a variety of applications, especially in the delivery and controlled release of various drugs. These compounds present a major obstacle to the treatment of many diseases and have a pivotal role in the future of personalized medicine. In the present study, adsorption and delivery of acyclovir (ACV) on pristine and modified magnetic nanoparticles are investigated. The as-synthesized magnetite nanoparticles are decorated with 3-(triethoxysilyI)-propylamine prior loading of ACV and samples are characterized by means of SEM, TEM, VSM, DLS, and zetametry studies. VSM and zeta potential studies show that ACV decreases the saturation magnetization and zeta potential of magnetite nanoparticles. Then, adsorption of ACV in phosphate buffered saline was examined and effects of some variables including pH, loading time and temperature arc briefly investigated. Our experimental results revealed the best loading (-80%) can be achieved at pH 9 at 39 degrees C after 5 h. The loading efficacy may be assigned to the increment of hydrogenic interactions under the loading process. Eventually, a DFT study was fully investigated to provide important theoretical parameters related to the adsorption process. The performed computations on pristine and doped Fe3O4 nanoparticles prove strong interactions between nitrogen and oxygen atoms of acyclovir with Fe+3 ions of magnetic nanopartides. Moreover, additional hydrogen bonds between active sites of the adsorbed drug molecule and Fe3O4 fragments lead to a significant adsorption and stabilization of the obtained configurations. The nature of intermolecular interactions, electron densities, and Lapladans is also fully investigated at the bond critical points. Natural bond orbital analysis confirms that acydovir can be adsorbed on the surface of Fe3O4 nanoparticle with a charge transfer from acyclovir to the nanopartide. In addition, the modified and doped Fe3O4 nanoparticles can absorb drug molecules more strongly compared to the pristine counterpart and generate stable configurations. Interestingly, doping with Zn atom results in an electronic hole, hence, the conductivity of the Fe3O4 may be enhanced. Therefore, Zn impurities can introduce local states inside the E g and improve reactivity of magnetic nanostructures towards adsorption process. Therefore, the examined metal-doped magnetic nanoparticles in this study can be applied as promising nanobiosensors for detection and delivery of ACV in medicine. (C) 2020 The Authors. Published by Elsevier B.V.