Biological activity of PdNPs derived from hemicellulose via microwave assisted green synthesis

Abstract

In recent era, synthesis of nanoparticles through green method has gained more attention as it is an environmentally friendly approach. Bio-synthesis of palladium nanoparticles (PdNPs) through single step and environmental benign microwave irradiation technique, using hemicellulose as reducing agent is reported. As synthesized PdNPs were characterized by various techniques such as FTIR, UV–Visible spectroscopy, XRD, SEM and TEM to confirm the formation of PdNPs for studying its biological activity. From UV–Visible spectra, it is observed that a SPR (Surface Plasmon Resonance) band at 280–300 ​nm clearly shows the formation of Pd nanoparticles. This was supported by FTIR as the wavenumbers observed at 473,524 and 616 ​cm−1corresponds to the metal stretching and bending frequencies. The phase formation and crystallinity of the PdNPs was studied using XRD. The observed (hkl) values (100), (111), (200) and (220) planes corresponds to the face centered cubic (fcc) structure of Pd (JCPDS No: 05–0681). Also, a well-defined and sharp reflections shows that, PdNPs are crystalline nature. The morphology of the PdNPs was studied through FESEM indicatesthe obtained particles are spherical in shape and seems to be agglomerated. The particle size of the PdNPs was measured through HRTEM and the average size was found to 10 ​nm. Further, PdNPs are used in the biological activity, it shows good antibacterial activity against both Gram-positive and Gram-negative bacteria's E. coli, Salmonella typhi, S. aureusand B. Subtilis B. shows maximum inhibition 21.40 ​mm. In addition, cytotoxic effects on MDA- MB 231, HepG2 and HeLa cells (survivability of cells is found MDA-MB 231 ​= ​30%, HepG2 ​= ​50% and HeLa ​= ​60%) were examined by series of assay. Overall, the present studies reveals that PdNPs are showing effective antibacterial activity and low cytotoxic.