K. Prasad

Plant system: Nature's nanofactory

Three categories of plants growing under three different extreme conditions were taken for assaying their promises to undertake nano-transformation. It was found that all of them successfully synthesize silver nanoparticles. The synthesis was performed akin to room temperature. X-ray and transmission electron microscopy analyses were performed to ascertain the formation of silver nanoparticles. X-ray analysis indicated that silver nanoparticles have FCC unit cell structure. Individual nanoparticles having the particle sizes of 2-5 nm were found. Possible involved mechanisms for the synthesis of silver nanoparticles from above plant systems have also been proposed.

Synthesis of TiO2 nanoparticles using microorganisms

A low-cost green and reproducible microbes (Lactobacillus sp. and Sachharomyces cerevisae) mediated biosynthesis of TiO(2) nanoparticles is reported. The synthesis is performed akin to room temperature in the laboratory ambience. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of TiO(2) nanoparticles. Individual nanoparticles as well as a few aggregate having the size of 8-35 nm are found. Concentric Scherrer rings in the selected area electron diffraction pattern indicated that the nanoparticles are having all possible orientations. A possible involved mechanism for the biosynthesis of nano-TiO(2) has also been proposed in which pH as well as partial pressure of gaseous hydrogen (rH(2)) or redox potential of the culture solution seems to play an important role in the process.

Green Synthesis of Silver Nanoparticles Using Cycas Leaf

ABSTRACT A green, low-cost, and reproducible Cycas leaf–negotiated synthesis of silver nanoparticles is reported. X-ray and transmission electron microscopy (TEM) analyses are performed to ascertain the formation of Ag nanoparticles. Nanoparticles almost spherical in shape having the size of 2–6 nm are found. Rietveld analysis to the X-ray data indicated that Ag nanoparticles have fcc unit cell structure. Ultraviolet (UV)-visible study revealed the surface plasmon resonance at 449 nm. An effort has been made to understand the possible involved mechanism for the biosynthesis of Ag nanoparticles. Present procedure offers the benefit of eco-friendliness and amenability for large-scale production through scaling up.

Biosynthesis of CdS nanoparticles: An improved green and rapid procedure.

A low-cost green and reproducible microbes (Lactobacillus sp. and Sachharomyces cerevisiae) mediated biosynthesis of CdS nanoparticles is reported. The synthesis is performed akin to room temperature in the laboratory ambience. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of CdS nanoparticles. Individual nanoparticles as well as a few aggregate having the size of 2.5-5.5nm are found. UV-vis spectroscopy study revealed the surface plasmon resonance at 393 and 369nm respectively for Lactobacillus and yeast assisted synthesis of CdS nanoparticles. The absorbance spectra were used to estimate the values of optical band gap and particle size of CdS nanoparticles. A possible involved mechanism for the biosynthesis of CdS nanoparticles has also been proposed.

Biosynthesis of silver nanoparticles using Eclipta leaf

A green, low‐cost and reproducible Eclipta leaves negotiated synthesis of silver nanoparticles is reported. The synthesis is performed at room temperature. X‐ray and transmission electron microscopy analyses are performed to ascertain the formation of Ag nanoparticles. Nanoparticles almost spherical in shape having a size of 2–6 nm are found. UV‐visible study revealed the surface plasmon resonance at 419 nm. The lattice strain is estimated to be 0.0045 using Williamson‐Hall approach. The use of Eclipta for the synthesis of silver nanoparticles offers the benefit of ecofriendliness and amenability for large scale production through scaling up.

Biosynthesis of metal and oxide nanoparticles using Lactobacilli from yoghurt and probiotic spore tablets

Green, low‐cost, and reproducible Lactobacillus‐mediated biosynthesis of metal and oxide nanoparticles are reported. Silver and titanium dioxide nanoparticles are synthesized using Lactobacillus sp. procured from yoghurt and probiotic tablets. The synthesis is performed akin to room temperature in the laboratory ambience. X‐ray and transmission electron microscopy analyses are performed to ascertain the formation of metallic and oxide nanoparticles. Individual nanoparticles having the dimensions of 10–25 nm (n‐Ag) and 10–70 nm (n‐TiO2) are found. The mechanism involved for the synthesis of metallic and oxide nanoparticles has also been discussed.

Biosynthesis of Sb2O3 nanoparticles: A low-cost green approach

A low-cost green and reproducible microbe (Lactobacillus sp.)-mediated biosynthesis of Sb(2)O(3) nanoparticles is reported. The synthesis was performed at around room temperature. X-ray and transmission electron microscopy analyses were performed to ascertain the formation of Sb(2)O(3) nanoparticles. X-ray analysis indicated that Sb(2)O(3) nanoparticles had a face-centered cubic unit cell structure. Individual nanoparticles as well as a few aggregates of 3-12 nm were found. A possible mechanism for the synthesis of nano Sb(2)O(3) is proposed.