ABSTRACT
Plant mediated green synthesis of silver nanoparticles (AgNPs) holds promising applications in the field of Biomedicine, Food packaging and Wound healing. In the present investigation, biofabrication of AgNPs was performed using the aqueous extracts of Campsis sp. (Family Bignoniaceae) leaves and flowers growing in the premises of Kirori Mal College, University of Delhi, Delhi. Optimization of AgNPs was performed to analyse the varying effect of pH (6.0, 8.0, 10.0) and silver salt concentration (2mM, 4Mm and 6Mm) in controlling the shape and size of AgNPs which in turn governs their further applications. Interestingly, change in colour of the reaction mixture from pale yellow to reddish brown indicated the formation of AgNPs. These AgNPs were further characterized by UV-Visible spectroscopy and showed peak in the range of 400-450 nm which confirmed the synthesis of silver nanoparticles. Dynamic light scattering and zeta potential analysis (DLS-Zeta) confirmed the size of AgNPs around 200-300 nm. A significant zone of inhibition was observed for both Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacterial strains which revealed the antimicrobial potential of Campsis sp. AgNPs. Therefore, Campsis AgNPs may provide a green, eco-sustainable alternate method for sustainable production of nanomaterials for biomedical applications. These AgNPs may also show tremendous applications in food packaging, wound healing and biomedical fields.
ABSTRACT
The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is one of the most serious cosmopolitan pests of cruciferous plants. It causes severe damage to crop quality and production, with estimated global losses of 20-40% per year. Consumer preference regarding pest-free and uncontaminated crop, unavailability of highly competitive natural enemies as well as migratory nature of DBM has obligated for the mandatory use of insecticides. The over reliance and indiscriminate use of chemical insecticides to control DBM has lead to development of resistance against almost all the modern insecticides. In addition, it has also developed resistance against most of the Bt strain. To overcome the problem of resistance, there is an urgent need for new and highly efficient method to control DBM which must be eco-friendly, cost effective and has minimum impact on the environment. One of such alternatives is nanotechnology which fulfil all the criteria to become an ideal insecticide or delivery system for insect pest management especially DBM. Nanotechnology offers great improvement in the field of pesticides as it is less toxic, shelf-life enhancement and higher water solubility. Loading of Indoxacarb on nanoparticles are reported to be highly effective they suppressed the activity of detoxification enzymes such as GST, CarE, and P450. Green synthesis of AgNPs, Single walled carbon nano tube (SWCNT) also exhibits larvicidal and pupicidal effect. These are also reported to adversely affect food consumption, growth, pupation and fecundity of P. xylostella.These nanoparticles have been found to be more stable, also the controlled release of active ingredient for a long time and provides target specific control of P. xylostella for solving adverse situations ofthe crop fields like less food security, lesser food productivity and environmental imbalance.