Larvicidal and Antibacterial Efficacy of Green Synthesized Silver Nanoparticles Using Aqueous Leaf Extract of Cinnamomum Verum

Abstract

Introduction: Green synthesized silver nanoparticles (Ag NPs) have wide applications in current scenario. The present study used aqueous extracts of Cinnamomum verum leaves for the green synthesis of silver nanoparticles.

Objectives: The study focused on the investigation of antibacterial and larvicidal potentials of green synthesized silver nanoparticles of C. verum aqueous leaf extracts against bacterial pathogens and Aedes aegypti’s (Diptera: Culicidae) fourth instar larvae respectively.

Methods: Fourth instar larvae of A. aegypti were exposed to various concentrations of Cinnamomum-Ag NPs (50, 100, 200, 400 and 800 ppm) and distilled water was maintained as control in two timespans namely 24 hours and 48 hours exposure. The antibacterial activity of green synthesized Ag NPs using C.verum leaf extract was carried out with disc diffusion method

Results: The results obtained from scanning electron microscopy, X-ray diffraction and Fourier transform infrared support the biosynthesis and characterization of silver nanoparticles. Transformation of colour from pale yellow to brick red of the leaf extract and AgNO₃ solution showed the formation of Cinnamomum-Ag NPs. Significant mortality occurred at all concentrations except 50 ppm during the 24 hour treatment and at all concentrations during the 48-hour treatment. The LD50 value was found to be 208.1 ppm (95% confidence limit between 175.34 and 249.67 ppm). Green synthesized Cinnamomum-Ag NPS showed antimicrobial effect against Streptococcus mutans (14mm), Staphylococcus aureus (8mm) and Pseudomonas aeruginosa (7mm).

Conclusions: The results suggests that Cinnamomum-Ag NPS is a potent larvicide against A. aegypti and an effective antibacterial agent.