Biomass-based magnetic fluorescent nanoparticles: One-step scalable synthesis, application as drug carriers and mechanism study.

A biomass-based magnetic fluorescent nanoparticle (MFNPs) was successively in situ synthesized via a one-step high-gravity approach, which constructed by a magnetic core of Fe3O4 nanoparticles, the fluorescent marker of carbon dots (CDs), and shells of chitosan (CS). The obtained MFNPs had a 10 nm average diameter and narrow particle size distribution, low cytotoxicity, superior fluorescent emission and superparamagnetic properties. The encapsulating and release 5-fluorouracil experiments confirmed that the introduction of CS/CDs effectively improved the drug loading capacity. Mechanism and kinetic studies proved that: (i) the monolayer adsorption was the main sorption mode under the studied conditions; (ii) the whole adsorption process was controlled by intra-liquid diffusion mass transfer and governed by chemisorption; and (iii) the release process was controlled by Fickian diffusion. These results demonstrated this method to one-step continuously produce MFNPs and the construction of non-toxic nanostructure possessed great superiority in currently Nano-delivery systems, which would show high application value in targeted drug delivery, magnetic fluid hyperthermia treatment, magnetic resonance imaging (MRI), in vitro testing and relative research.

Removal of heavy metal ions by magnetic chitosan nanoparticles prepared continuously via high-gravity reactive precipitation method.

This study aimed to provide a continuous method for the preparation of magnetic Fe3O4/Chitosan nanoparticles (Fe3O4/CS NPs) that can be applied to efficient removal of heavy metal ions from aqueous solution. Using a novel impinging stream-rotating packed bed, the continuous preparation of Fe3O4/CS NPs reached a theoretical production rate of 3.43kg/h. The as-prepared Fe3O4/CS NPs were quasi-spherical with average diameter of about 18nm and saturation magnetization of 33.5emu/g. Owing to the strong metal chelating ability of chitosan, the Fe3O4/CS NPs exhibited better adsorption capacity and faster adsorption rates for Pb(II) and Cd(II) than those of pure Fe3O4. The maximum adsorption capacities of Fe3O4/CS NPs for Pb(II) and Cd(II) were 79.24 and 36.42mgg-1, respectively. In addition, the Fe3O4/CS NPs shown excellent reusability after five adsorption-desorption cycles. All the above results provided a potential method for continuously preparing recyclable adsorbent with a wide prospect of application in wastewater treatment.