Green synthesis of Silver nanoparticle by Acanthus ilicifolius mangrove plant against Armigeressubalbatus and Aedesaegypti mosquito larvae

To identify the larvicidal activities of silver nanoparticles synthesized with Acanthus ilicifolius (A. ilicifolius) leaf extract against the larvae of Armigeressubalbatus and Aedesaegypti. In vitro larvicidal activities such as LC50 and LC90 were assessed for the A. subalbatus  and Ae.aegypti larval species. Further, characterization using different techniques such as UV, SEM,EDAX, XRD and FTIR analysis were carried out for the synthesized silver nanoparticles. The LC50 value of the synthesized silver nanoparticle was determined as0.532 and 0.754mg/L for A. subalbatus and Ae. aegypti respectively. Further, the LC90 values are also determined as 2.13 and 5.98mg/L for A. subalbatus and Ae. aegypti respectively. The synthesized silver nanoparticles have maximum absorption at 420 nm with the average diameter ˃180 nm. The Energy Dispersive Analysis of X-rays (EDAX) spectrum revealed the presence of silver metal in synthesized nanomaterials. The XRD data showed 2θ intense values with various degrees such as 37.10°, 47.66°, 63.97° and 70.01°. The FTIR data showed prominent band at 3,400 cm-1 and is assigned to the O–H stretching of H-bonded alcohols and phenols. The band at 2,925 cm-1 is attributed to O–H stretching of carboxylic acids. The band at 1,616 cm-1, corresponds to the N–H bending of primary amines. The bands at 1,444 and 1,521 cm-1 are related to the C–C stretching of aromatic ring structure and the characteristic peak at 1,360 cm-1corresponds to the C–N stretching of aromatic amine group whereas in the region of 1,150–1,282 cm-1 are corresponding to the C–C stretching alcohols, carboxylic acids, ethers and esters. The significance of above results clearly indicate that no toxicity developed biosynthesis of silver nanoparticles with leaf aqueous extract of A. ilicifolius  provides potential source for the larvicidal activity against mosquito borne diseases.