Eco-friendly synthesis of silver nanoparticles from the red seaweed Gelidiella acerosa and their impact on larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus
摘要
Gelidiella acerosa, a tropical marine red alga, is abundantly found in the Indian, Pacific, and Atlantic Oceans. Silver nanoparticles (AgNPs) synthesized from G. acerosa were characterized by UV spectrophotometry, FTIR, XRD and SEM with EDX. After 24 h of exposure, the G. acerosa-AgNPs demonstrated significant mosquito larvicidal effects on 4th instar larvae of the mosquito Culex quinquefasciatus, with LC50 and LC90 values of 26.95 μg mL-1 and 38.27 μg mL-1, respectively. The G. acerosa-AgNPs also exhibited substantial activity against Anopheles stephensi larvae. Similarly, G. acerosa-AgNPs caused high mortality in Aedes aegypti larvae, with LC50 and LC90 values of 39.34 μg mL-1 and 73.01 μg mL-1 respectively. Additionally, the aqueous extract of G. acerosa exerted potent larvicidal activity against An. stephensi, with LC50 and LC90 values of 47.04 μg mL-1 and 134.65 μg mL-1, followed by values of 63.12 μg mL-1 and 132.78 μg mL-1 in Ae. aegypti and 87.41 μg mL-1 and 177.39 μg mL-1 in Cx. quinquefasciatus. Histopathological analysis of the NPs-treated larvae revealed disorganized and significantly damaged tissue layers. The 24 h mortality test on Artemia salina nauplii indicated dose-dependent toxicity, with an LC50 value of 187.68 μg mL-1, suggesting medium toxicity of the NPs. These findings indicate that AgNPs synthesized from G. acerosa could be promising for the formulation of mosquito control agent in future.