Larvicidal activity of phyto-synthesized silver nanoparticle bio-reduced by Morinda citrifolia (noni) leaf extract against Aedes aegypti Linn larvae

Nanotechnology has exhibited tremendous range of application within the biomedical field, one of which is the larvicidal activity on different species. The use of plants to synthesize metal nanoparticles have gained acknowledgement for it has biocompatibility, lesser toxicity, greener and ecological procedures. This study utilized Morinda citrifolia, commercially known as Noni plant, for the bio-reduction of silver nanoparticles, and was tested for its larvicidal activity on Aedes aegypti, the potent dengue viruscarrier. The synthesized nanoparticles were subjected to UV- Visible spectrophotometer, Fourier Transform Infrared Spectroscopy and Field Emission Scanning Electron Microscopefor further characterization. Its larvicidal activity against the varied concentrations was also determined using third instar of Aedes aegyptilarvae. The synthesized silver nanoparticles were characterized by its surface plasmon resonance (SPR), with an absorbance peak of 451 nm in the UV–Vis spectrum. FTIR analysis showed the existence of proteins accountable for creation of nanoparticles that plays a significant role in the development and stabilization of the produced silver nanoparticles. FESEM result images shows the synthesized nanoparticles produced have mostly spherical in its morphology and had an average size of 92 ± 5 nm. Silver nanoparticles produced from M. citrifolia leaf extract demonstrated larvicidal activity on the dengue vector, A. aegypti. Observed lethal concentrations (LC50 and LC90) towards the third instar larvae were 1.629 and 15.663 mg/L of nanoparticles respectively, after the 48 hour exposure period. Results suggest that the Morinda citrifolia leaf extract used in the biosynthesis of silver nanoparticles has larvicidal properties against Aedes aegypti.

Keywords: biosynthesis, larvicidal, Aedes aegypti, Morinda citrifolia, silver nanoparticles