Synthesis and characterisation of Celosia cristata L. flower extract-based silver nanoparticles as effective antimicrobial agent for plant protection M Sakil, V Abha, K Neelesh Plant Science Today, 2026 Plant systems are a natural reservoir of phytochemicals that may act as agents for reducing silver ions into nanoparticles. This study reports the green synthesis and characterisation of silver nanoparticles using Celosia cristata L. flower extract and evaluates their antimicrobial efficacy against key plant pathogens: Alternaria solani, Fusarium graminearum and Xanthomonas oryzae pv. oryzae. The biosynthesis involved the use of phytochemicals as natural reducing/stabilising agents and silver nitrate. The formation of silver nanoparticles was indicated by a colour change and confirmed by a surface plasmon resonance peak at 426 nm in UV–Visible spectroscopy. X-ray diffraction analysis revealed a face-centred cubic crystalline structure with dominant (111) orientation and transmission electron microscopy showed mostly spherical nanoparticles with an average size of 13 nm. Fourier-transform infrared spectroscopy identified functional groups responsible for capping and stabilisation. Antimicrobial activity was demonstrated through agar well diffusion with notable inhibition zones: 26 ± 1.00 mm (A. solani), 23 ± 2.00 mm (F. graminearum) and 21 ± 0.5 mm (X. oryzae pv. oryzae). Minimum inhibitory concentrations (MICs) as observed in the investigation was 78.1 mg/mL (for A. solani) and 156.2 mg/mL (for F. graminearum and X. oryzae pv. oryzae). The findings highlight the potential of C. cristata-derived silver nanoparticles as eco-friendly biocontrol agents in sustainable agriculture, offering a promising alternative to conventional chemical pesticides.
Activity of silver nanoparticles synthesized using aqueous leaf extract of Solanum Nigrum against potential human pathogenic bacteria Biochemical and Cellular Archives, 2016
Antibacterial activity of silver nanoparticles synthesized using weeds Gautam Kumar, Abha Verma, Prakash Joshi, Arvind Arya Medicinal Plants, 2013 Biologically synthesized silver nanoparticles are being widely used in the field of medicine. This report focuses on extracellular biosynthesis of silver nanoparticles using leaf extracts of four commonly occurring weed. The synthesis of silver nanoparticles was detected by changing colour of plant leaf extracts from green to brown after treatment with AgNO3 and UV-Vis spectrophotometric analysis. These phyto-synthesized silver nanoparticles were tested for their antibacterial activity using agar well diffusion method. The test bacteria were E. coli, Staphylococcus aureus and Bacillus sp. Among all the test organisms Bacillus sp. followed by Staphylococcus aureus were found to be susceptible to all the silver nanoparticles with maximum inhibition by Sonchus asper whereas E. coli was least affected. The results suggest use of phytoextracts as an easy alternative for silver nanoparticles synthesis over the conventional methods.
