Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

A novel hybrid nanostructured material comprising superparamagnetic magnetite nanoparticles (MNPs) and pectin was synthesized by crosslinking with Ca2+ ions to form spherical calcium pectinate nanostructures, referred as MCPs, which were typically found to be 100–150nm in size in dried condition, confirmed from transmission electron microscopy and scanning electron microscopy. The uniform size distribution was revealed from dynamic light scattering measurement. In aqueous medium the MCPs showed swelling behavior with an average size of 400nm. A mechanism of formation of spherical MCPs is outlined constituting a MNP–pectin interface encapsulated by calcium pectinate at the periphery, by using an array of characterization techniques like zeta potential, thermogravimetry, Fourier transformed infrared and X-ray photoelectron spectroscopy. The MCPs were stable in simulated gastrointestinal fluid and ensured minimal loss of magnetic material. They exhibited superparamagnetic behavior, confirmed from zero field cooled and field cooled profiles and showed high saturation magnetization (Ms) of 46.21emu/g at 2.5T and 300K. Ms decreased with increasing precursor pectin concentrations, attributed to quenching of magnetic moments by formation of a magnetic dead layer on the MNPs. ► In the present investigation we have developed a facile route to synthesize a novel, low cost calcium pectinate nanostructure functionalized with SPIONs (magnetite nanoparticles). ► Though there are sufficient scientific illustrations on polymer as well as biopolymers coated on SPIONs for various biomedical applications, the one presented here, is novel of its kind as it is considered to offer a new dimension to the magnetic responsive properties of calcium pectinate nanomaterials towards biomedical applications, especially as a potential carrier for magnetically targeted drug delivery to colon specific sites. ► The synthesis of these nanostructured materials has probably evoked a new insight about the interaction between pectin and magnetite nanoparticles at their interface, which led to only 10% reduction of their saturation magnetization as compared to as synthesized magnetite nanoparticles without any polymer interaction. ► We have proposed a mechanism towards the formation of such novel nanostructured materials using several characterization techniques. ► It is therefore expected that our present investigation would be appreciated by the readers of JMMM.