Study Of Biochemical Fabrication And Applications Of Metal-based Nanoparticles And Nanocomposites

Rapidly increasing resistance of micro-organisms towards most of available drugs and an alarming level of water pollution due to expanding industrialization,there is an immense need of new therapeutic agents and methodologies to combat this situation.Therefore,this dissertation presents a study of green fabrication method to synthesize highly active metal nanoparticles and nano-composites that has many advantages over traditional synthetic methods such as it is cost effective,simple and safer approach.This study is a based on three main projects each of which is further categorized into three sections i.e.(1)synthesis and methodology,(2)Characterization and(3)applications of biofabricated metal nanoparticles and nanocomposites as antibacterial agent and an adsorbent to remove heavy metal from aqueous medium.·Project(?)was aimed to synthesize highly active iron oxide NPs(nanoparticles)using Punica granatum peel extract.In order to obtained the best activity,morphology and size of biochemically capped iron oxide NPs were optimized at three different conc.of peel extract(20 mL,40 mL and 60 mL).The findings revealed that the plant extract conc.plays an important role to control the morphology,size and dispersion of the nanomaterial.Hence,40 mL concentration of peel extract@0.15 M solution of ferric FeCl3·6H2O is the best composite to obtained smallest size and high degree of dispersion.The biogenic FeNPs were tested for their size dependent antibacterial activity.FT-IR analysis confirmed that he phytochemicals from the plan source play important role in reduction and stabilization of FeNPs.SEM analysis showed the effect of plant peel concentration on the morphology and dispersion of FeNPs.UV-Vis,XRD,and EDS also determined various aspects of biogenic FeNPs.The green synthesized FeNPs were tested as an antibacterial agent against Pseudomonas aeruginosa.The results indicated a strong antibacterial property of FeNPs.Moreover,the optimized FeNPs(synthesized using 40 mL peel extract solution)were found to show the maximum antibacterial activity i.e.22(±0.5)mm than FeNPs synthesized using 20 mL and 60 mL peel extract 18(±0.4)mm and 14(±0.3)mm respectively.Additionally,biogenic FeNPs exhibited amazing ROS generation property.FeNPs were found to show no hemolytic activity that affirms their biocompatibility.·Project(?)presents another green-oriented fabrication of PdNPs using three different volumes of Acacia nilotica plant leaf extract(i.e.10 mL,15 mL and 20 mL).UV-Vis,FTIR,XRD,HRTEM,SEM,and EDS techniques were utilized to characterized PdNPs.The data confirmed a substantial involvement of phytochemicals in the formation and stabilization of PdNPs.Moreover,the biogenic PdNPs were found to be crystalline in nature,smaller in size and spherical in shape.Furthermore,PdNPs synthesized at optimum condition(using 15 mL plant extract)showed strong antibacterial activity(18 mm diameter of zone of inhibition)against Escherichia coli than the PdNPs synthesized using 10 mL and 20 mL plant extract(i.e.12 mm and 14 mm zone of inhibition respectively).The results obtained from MIC(i.e.0.062 mg/mL),ROS,no hemolytic risk and antioxidant activity(i.e.86%trapping of DPPH)further ascertain the efficiency and biocompatibility of the PdNPs.·Project(?)also presents a novel,simple and ecofriendly(green)method for preparation of Pd@ZnO nanocomposite.This project aimed to introduce phytoconstituents of plant extract(Saccharum arundinaceum)that were expected to prevent the agglomeration of nanoparticles irrespective to the concentration of individual nanoparticles.The synthesized Pd@ZnO nanocomposite was evaluated for its adsorption efficiency for Cr(VI)removal from aqueous solution and its photocatalytic activity in the reduction of organic dye(MB).Additionally,the recyclability of green synthesized Pd@ZnO nanocomposite was determined.The results obtained highlight the pH-specific reaction of Cr(VI)by Pd@ZnO adsorbent with Cr(?)and the removal efficiency varies at different pH range.Moreover,adsorption isotherm data was fitted well to Langmuir,Freundlich,and Flory-Huggins models.The adsorption-desorption studies for 4 successive cycles and 95%photocatalytic reduction of methylene blue using Pd@ZnO nanocatalyst exhibit good reusability and photocatalytic property of Pd@ZnO nanocomposite.The results indicate that the green synthesized Pd@ZnO nanomaterial is quite efficient against inorganic and organic pollutants both as an adsorbent as well as a photocatalyst respectively.