Green silver nano-particles: synthesis using rice leaf extract, characterization, efficacy, and non-target effects
Totan Adak1, Harekrushna Swain2, Sushmita Munda3
1Crop Protection Division, ICAR-National Rice Research Institute (formerly Central Rice Research Institute), Cuttack, 753006, India. totanadak@gmail.com.
Environmental Science and Pollution Research International
|September 18, 2020
Summary
Green synthesis of silver nanoparticles (AgNPs) using rice leaf extract offers a potent, eco-friendly pesticide alternative. These AgNPs effectively combat rice pathogens with minimal soil microbial impact, comparable to commercial fungicides.
Area of Science:
- Green Chemistry and Nanotechnology
- Agricultural Science and Crop Protection
Background:
- Development of sustainable and eco-friendly pesticides is crucial for modern agriculture.
- Silver nanoparticles (AgNPs) show promise as antimicrobial agents but require green synthesis methods.
- Purple-colored rice leaves are rich in phenols, anthocyanins, and flavonoids, potential natural reducing and capping agents.
Purpose of the Study:
- To synthesize silver nanoparticles (AgNPs) using purple rice leaf extract via a green chemistry approach.
- To characterize the synthesized AgNPs and optimize their production parameters.
- To evaluate the efficacy of AgNPs against major rice pathogens and assess their impact on soil microbial health.
Main Methods:
- Green synthesis of AgNPs from silver nitrate using purple rice leaf extract.
- Characterization of AgNPs using SEM, EDX, and FTIR spectroscopy.
- Optimization of reaction parameters: incubation time (48h), AgNO3:extract ratio (9:1 v/v), and temperature (20-30°C).
- Assessment of AgNP size, zeta potential, and antimicrobial activity against Rhizoctonia solani, Xanthomonas oryzae pv. Oryzae, and Helminthosporium oryzae.
- Evaluation of AgNP effects on soil microbial biomass carbon and soil enzymes.
Main Results:
- Successful green synthesis of AgNPs confirmed by SEM, EDX, and FTIR, indicating biomolecular capping.
- Optimized synthesis yielded AgNPs with hydrodynamic sizes of 36-107 nm and zeta potentials from -16.61 to -29.45 mV.
- Synthesized AgNPs demonstrated significant control over key rice pathogens.
- Higher concentrations of AgNPs showed minor negative effects on soil microbes, comparable to the commercial fungicide carbendazim.
Conclusions:
- Purple rice leaf extract effectively facilitates the green synthesis of stable silver nanoparticles.
- The synthesized AgNPs exhibit potent, broad-spectrum pesticidal activity against major rice diseases.
- AgNPs present a viable, eco-friendlier alternative to conventional chemical pesticides in rice cultivation.
