The present study is to synthesize iron oxide nanoparticles on different polysaccharide templates calcined at controlled temperature, characterizing them for spectroscopic and magnetic studies leading to evaluate their antibacterial property. The synthesized iron oxide nanoparticles were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy, high resolution scanning electron microscopy (HRSEM), high resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer. The iron oxide nanoparticles were tested for antibacterial activity against grampositive and gram-negative bacterial species. The XRD confirms the crystalline nature of iron oxide nanoparticles with the mean crystallite size of 10 nm. The functional groups of the synthesized iron oxide nanoparticles were 547, 543 and 544 cm -1 characterizing the Fe-O and the broad bands at 3,398, 3,439 and 3,427 cm -1 were attributed to the stretching vibrations of hydroxyl group absorbed by iron oxide nanoparticles. HRTEM analyses revealed that the average particle size of the hematite nanoparticles are about 85, 92 and 77 nm for AF, DF and GF, respectively, which was a coincident with the results obtained from the HRSEM analysis. Magnetic measurement exhibited ferromagnetic behavior of the a-Fe 2 O 3 at the room temperature with higher coercivity of H C = 2,303, 2,333 and 1,019 Oe for AF, DF and GF, respectively. Antibacterial test showed the inhibition against Aeromonas hydrophila and Escherichia coli with significant antagonistic activity.

Superparamagnetic iron oxide nanoparticles (SPIONs) have been synthesized using co-precipitation method. Their microstructure and dielectric properties were studied. The sugar solutions like glucose, fructose and sucrose were used as stabilizers to control the size of the SPIONs. The crystal structure and grain size of the particles were determined by X-ray diffraction. The magnetic studies of the samples were carried out using the vibrating sample magnetometer and their surface morphology was studied by HRTEM, FE-SEM and zeta potential. The dielectric properties of glucose-SPIONs (GF), fructose-SPIONs (FF) and sucrose-SPIONs (SF) were investigated in the frequency range of 10 Hz to 5 MHz at selected temperatures. The FF showed a high dielectric constant of 62 at 1 MHz and the dielectric properties of SPIONs were found to have been significantly improved, especially in the low frequency regime according to the Maxwell-Wagner interfacial polarization. The AC conductivity measurements revealed that the electrical conduction depends on both frequency and temperature. Impedance analysis was carried out using Cole-Cole plot and the conduction mechanism of the studied compounds was explained. R and C values were further calculated using RC-circuit.

Superparamagnetic iron oxide nanoparticles (SPIONs) have been prepared without using surfactants to assess their stability at different time intervals. The synthesized particles were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, ultraviolet-visible-near infrared spectroscopy, and energy dispersive spectroscopy. Field emission scanning electron microscopy and high-resolution transmission electron microscopy images of the samples were also investigated. The average particle size was measured to be 12.7 nm even in the polydispersed form. The magnetic and dielectric characteristics of the Fe 3 O 4 nanoparticles have also been studied and discussed in detail.