Synthesis and characterization of chitosan/iron oxide nanocomposite for biomedical applications.

The structural and optical properties of metal oxide nanoparticles exhibit remarkable changes when coated with organic polymers. In this work, we report the preparation of chitosan (CS) coated iron oxide nanocomposite using rutin by a facile greener route. The formation of iron oxide nanoparticles (FeO NPs) and CS coated iron oxide nanocomposite (CS-FeO) were preliminarily confirmed by color change and UV-Visible spectroscopy. FE-SEM images of FeO NPs revealed rod shaped agglomerated particles whereas CS-FeO nanocomposite showed rod shaped agglomerated small grains. TEM analysis revealed that the size of the nanoparticles varies from 20 to 90 nm. The observed bands at 500-800 cm-1 in the FTIR spectrum indicated the presence of metal­oxygen (FeO) bond, whereas band at 1646 cm-1 indicated the presence of amino groups (-NH2) which confirms the CS in the prepared CS-FeO nanocomposite. The prepared nanoparticles showed potential antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens. The antioxidant activity of FeO NPs and CS-FeO nanocomposite was evaluated by DPPH and H2O2 assays. The percentage of antioxidant activity was increased with increasing concentration of FeO NPs and CS-FeO nanocomposite. CS-FeO nanocomposite exhibiting potentially better biomedical property than the uncoated FeO NPs indicates that CS-FeO nanocomposite is a promising bio-nanomaterial for many biological applications.

Surface active gold nanoparticles biosynthesis by new approach for bionanocatalytic activity.

In the present day, nanotechnology is one of the most promising leading scientific and potentials areas in modern key technology development toward to the humankind. The synthesis of noble metal nanoparticles (NPs) is an expanding research area due to the possible applications for the development of bio-medical applications. Eco-friendly approach for the biosynthesis of gold nanoparticles (AuNPs) using the aqueous extract from Ruellia tuberosa and Phyllanthus acidus (leaf and twig) for the first time. Surface active AuNPs were characterized by UV-Vis spectroscopy, FTIR (Fourier transform infrared) spectroscopy, DSC (differential scanning colorimetry), DLS (dynamic light scattering) and environmental SEM (scanning electron microscope) analysis at room temperature (RT). Enhanced surface plasmon resonance (SPR) absorbance UV visible optical spectra were detected in the range of 552, 548, 558 and 536 nm. SEM and DLS (transmission mode) analysis confirmed the morphology of the nanoparticles to be spherical with the average size in the range of 88.37, 94.31, 82.23 and 81.36 nm. Further they have enhanced the enzyme activity on α-amylase, cellulase, and xylanase. The results suggest that the phyto-fabricated AuNPs from R. tuberosa and P. acidus is simple, less expensive, eco-friendly, green synthesis and also can be exploited for the potential future industrial and bio-medical applications.