| Autor: |
Anil Kumar V; Department of Biotechnology, Acharya Nagarjuna University, Guntur 522 510, Andhra Pradesh, India., Ammani K; Department of Botany and Microbiology, Acharya Nagarjuna University, Guntur 522 510, Andhra Pradesh, India. ammani1960@gmail.com., Jobina R; Centre for Microbiology, School of Life Sciences, Pondicherry University, Pondicherry 605 014, India., Parasuraman P; Centre for Microbiology, School of Life Sciences, Pondicherry University, Pondicherry 605 014, India., Siddhardha B; Centre for Microbiology, School of Life Sciences, Pondicherry University, Pondicherry 605 014, India. |
| Abstrakt: |
Green synthesis of silver nanoparticles (AgNPs) using plant extracts has been achieved by eco-friendly reducing and capping agents. The present study was conducted to evaluate the larvicidal efficacies of AgNPs synthesized using aqueous leaf extracts of Excoecaria agallocha against dengue vector, Aedes aegypti . The 3 rd and 4 th instar larvae of A. aegypti were exposed to various concentrations of aqueous extracts of E. agallocha , synthesized AgNPs and also crude solvent extracts (methanol and chloroform) for 24 h. The formation of AgNPs using aqueous leaf extracts was observed after 30 min with a characteristic colour change. The results recorded from UV-Vis spectrum, XRD, FTIR, EDX, SEM and HR-TEM were used to characterize and confirm the biosynthesis of AgNPs. The highest larvicidal efficacy of synthesized AgNPs was observed against 3 rd instar larvae at LC 50 4.65 mg/L, LC 90 14.17 mg/L and 4 th instar larvae with a concentration of LC 50 6.10 mg/L, LC 90 15.64 mg/L. A significant larvicidal activity was also observed with crude methanolic extracts against 3 rd instar larvae at a concentration LC 50 41.74 mg/L, LC 90 123.61 mg/L and 4 th instar larvae at a concentration of LC 50 52.06 mg/L, LC 90 166.40 mg/L as compared to the chloroform extract. |
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