A.R. Srivastava

Nanocrystalline zinc oxide for the decontamination of sarin.

Nanocrystalline zinc oxide materials were prepared by sol-gel method and were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry, nitrogen adsorption and infrared spectroscopy techniques. The data confirmed the formation of zinc oxide materials of zincite phase with an average crystallite size of approximately 55 nm. Obtained material was tested as destructive adsorbent for the decontamination of sarin and the reaction was followed by GC-NPD and GC-MS techniques. The reaction products were characterized by GC-MS and the data explored the role of hydrolysis reaction in the detoxification of sarin. Sarin was hydrolyzed to form surface bound non-toxic phosphonate on the surface of nano-zinc oxide. The data also revealed the values of rate constant and half-life to be 4.12h(-1) and 0.16 h in the initial stages of the reaction and 0.361 h(-1) and 1.9h at the final stages of the reaction for the decontamination reaction on nanocrystalline ZnO.

Effect of calcinations temperature of CuO nanoparticle on the kinetics of decontamination and decontamination products of sulphur mustard.

Present study investigates the potential of CuO nanoparticles calcined at different temperature for the decontamination of persistent chemical warfare agent sulphur mustard (HD) at room temperature (30 ± 2 °C). Nanoparticles were synthesized by precipitation method and characterized by using SEM, EDAX, XRD, and Raman Spectroscopy. Synthesized nanoparticles were tested as destructive adsorbents for the degradation of HD. Reactions were monitored by GC-FID technique and the reaction products characterized by GC-MS. It was observed that the rate of degradation of HD decreases with the increase in calcination temperature and there is a change in the percentage of product of HD degradation. GC-MS data indicated that the elimination product increases with increase in calcination temperature whereas the hydrolysis product decreases.

Reactions of sulphur mustard and sarin on V1.02O2.98 nanotubes

Reactions of sulphur mustard and sarin were studied on the surface of V(1.02)O(2.98) nanotubes by gas chromatography and gas chromatography-mass spectrometry techniques. The V(1.02)O(2.98) nanotube samples were made by using hydrothermal method and characterized by scanning electron microscopy, nitrogen adsorption, X-ray diffractometry and thermogravimetry. Later, they were exposed to sulphur mustard and sarin separately at ambient temperature (30+/-2 degrees C). The data explored the formation of sulphoxide of sulphur mustard, thiodiglycol for sulphur mustard and isopropyl methyl phosphonic acid for sarin on V(1.02)O(2.98) nanotubes illustrating the role of oxidation and hydrolysis reactions in the decontamination.

Kinetics of degradation of sulfur mustard and sarin simulants on HKUST-1 metal organic framework

The applicability of HKUST-1 for the degradation of sulfur mustard and sarin simulants was studied with and without coadsorbed water. Degradation was found to be via hydrolysis and dependent on the nucleophilic substitution reaction, vapour pressure and molecular diameter of the toxicants.

Photocatalytic inactivation of spores of Bacillus anthracis using titania nanomaterials.

Studies on photocatalytic inactivation of spores of Bacillus anthracis have been carried out using nanosized titania materials and UVA light or sun light. Results demonstrated pseudo first order behaviour of spore inactivation kinetics. The value of kinetic rate constant increased from 0.4h(-1) to 1.4h(-1) indicating photocatalysis facilitated by addition of nanosized titania. Nanosized titania exhibited superior inactivation kinetics on par with large sized titania. The value of kinetic rate constant increased from 0.02 h(-1) to 0.26 h(-1) on reduction of size from 1000 nm to 16 nm depicting the enhanced rate of inactivation of Bacillus anthracis Sterne spores on the decrease of particle size.

Synthesis, characterization and photocatalytic activity of Ag–TiO2 nanoparticulate film

Ag–TiO2 nanoparticulate film was synthesized by dip coating followed by adsorption and photoreduction in UVA light, characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive analysis of X-rays, glancing angle X-ray diffractometry and UV-Vis absorption spectrophotometry techniques. The data indicated the presence of TiO2 particles of anatase phase of size varying from 5–15 nm, Ag nanoparticles of size varying from 10–20 nm, and also indicated the added visible light activity in Ag–TiO2 nanoparticle films. Photocatalytic degradation of methyl parathion (O,O-dimethyl O-(4-nitrophenyl) phosphorothioate), a well known pesticide in aqueous solution was studied using Ag–TiO2 nanoparticulate film and the data was compared with TiO2 nanoparticulate film. Photocatalytic degradation reactions demonstrated pseudo first order behaviour. Methyl parathion was found to be degraded initially to paraoxon which further was degraded to p-nitrophenol, trimethyl ester of phosphoric acid, trimethyl ester of phosphothioic acid, and finally to phosphate ion. Minute amounts of carbon dioxide and acetaldehyde were also detected.

Decontamination of Yperite using mesoporous mixed metal oxide nanocrystals.

Mixed metal oxide nanocrystals of AP-Al(2)O(3), AP-Al(2)O(3)-Fe(2)O(3), AP-Al(2)O(3)-V(2)O(5) and AP-Al(2)O(3)-CuO have been prepared by aerogel process. XRD data of prepared materials revealed the formation of nanocrystals with a size range of 3-15 nm diameters. N(2) BET investigations on these materials revealed larger values of surface area ranging from 350 to 540 m(2)/g. Reactivity of these nanocrystalline materials against Yperite was examined by gas chromatography, gas chromatography-mass spectrometry and infrared spectroscopy techniques. AP-Al(2)O(3)-Fe(2)O(3), AP-Al(2)O(3)-V(2)O(5) and AP-Al(2)O(3)-CuO nanocrystals exhibited superior decontamination properties against Yperite than AP-Al(2)O(3). The reactions exhibited pseudo first order behaviour. 100% of Yperite was found to be decontaminated on Al(2)O(3)-Fe(2)O(3), Al(2)O(3)-V(2)O(5) and Al(2)O(3)-CuO where only 75% of the same was found to be decontaminated on AP-Al(2)O(3) within 40 h.

Surface plasmon resonance characterization of monoclonal and polyclonal antibodies of malaria for biosensor applications

Surface plasmon resonance (SPR) screening of monoclonal and polyclonal antibodies of Plasmodium falciparum (MoabPf and PoabPf) for recombinant Histidine rich protein-II antigen (Ag) of Pf (rHRP-II Ag) was conducted in a real-time and label-free manner to select an appropriate antibody (Ab) for biosensor applications. In this study 4-mercaptobenzoic acid (4-MBA) modified gold SPR chip was used for immobilizing the Ag and then Ab was interacted. SEM image showed modification of SPR chip with 4-MBA and EDAX confirmed the presence of 4-MBA on the SPR chip. Equilibrium constant (KD) and maximum binding capacity of analyte (Bmax) values for the interaction of MoabPf or PoabPf with the immobilized rHRP-II Ag were calculated and found to be 0.517 nM and 48.61 m° for MoabPf and 2.288 nM and 46.80 m° for PoabPf, respectively. In addition, thermodynamic parameters such as ΔG, ΔH and ΔS were determined for the interaction between rHRP-II Ag and MoabPf or PoabPf and the values revealed that the interaction is spontaneous, exothermic and driven by entropy. The kinetics and thermodymanic results of this study revealed that the interaction between MoabPf and rHRP-II Ag is more effective than that of PoabPf due to the fact that MoabPf was derived from a single epitope (single clone) whereas the PoabPf was from the mixture of a number of epitopes (polyclones). Finally, SPR methodology was developed for the sensing of malarial antibodies. The limit of detection was found to be 5.6 pg with MoabPf which was found to be the best in our study.