Laboratory analysis of Au–Pd bimetallic nanoparticles synthesized with Citrus limon leaf extract and its efficacy on mosquito larvae and non-target organisms

Abstract

The current study provides novel results on the synthesis of bimetallic nanoparticles (BNPs) of gold and palladium (Au–Pd) with an eco-friendly and non-toxic aqueous leaf extract of plant Citrus limon. The BNPs were characterized and toxicity bioassay was examined on the larvae of the pathogen vectors such as Anopheles stephensi and Aedes aegypti mosquitoes. The predation efficiency test was evaluated on the invertebrate non-target organisms such as natural predatory nymphs of dragonfly and damselfly. The results of material characterization using UV VIS spectroscopy confirmed the synthesis of Au–Pd BNPs with the appearance of the SPR bands. FT-IR spectroscopy indicates the presence of functional groups containing high amounts of nitro compounds and amines on the surface of BNPs. TEM result shows the presence of spherical polydisperse Au–Pd BNPs in the sample. The XRD pattern displayed the semi-crystalline nature and the changes in the hydrodynamic size and surface potential was determined for the sample at 0 h, 24 h, 48 h, and 72 h of synthesis through DLS and ZP analysis. Au–Pd BNPs Bioassay provided the effective lethal concentrations (LC50) against the I–IV instar larvae of An. stephensi and Ae. aegypti after 24 h, 48 h, and 72 h of exposure. The LC50 obtained from the larvicidal bioassay was used to test its effect on the predation efficiency of the selected nymphs which showed increased predation from 40 to 48 h of exposure as compared to the negative control. Hereby, we conclude that Au–Pd BNPs bioassay shows toxic mosquito larvicidal activity at the selected concentration with no lethal effect on the predation efficiency of the selected stage of the predatory non-target aquatic invertebrate insects.

Green adeptness in synthesis of non-toxic copper and cobalt oxide nanocomposites with multifaceted bioactivities

“…There are some studies which used nanoparticles of selenium (Cittrarasu et al 2021), zinc oxide (Amuthavalli et al 2021), Au-Pd bimetallic (Minal and Prakash 2020), but for these studies they used higher concentration of nanoparticles to get 100% mortality. As compared to above studies, our present investigation revealed 100% mortality of all the larval instars and pupae at very low concentrations of bio-nanocomposites.…”

Synthesis of Bimetallic Nanoparticles and Applications—An Updated Review

“…Similarly, synthesized Cu-Zn, ZnO-TiO and Ag-Ni bimetallic nanoparticles have been used as nano-pesticide/insecticide against cotton Mealybug [254], Spodoptera fruggiperda (an important pest of several crops) [255] and Lymphatic filariasis Vector [256]. In addition, Au-Pd have also shown larvicidal activity against mosquito larvae [257]. Another application of bimetallic nanoparticles in agriculture is food packaging.…”

Mosquito-Borne Diseases and Their Control Strategies: An Overview Focused on Green Synthesized Plant-Based Metallic Nanoparticles

“…It should be noted that modifications to the WHO standardized procedures are common. These variations concern mainly the operating conditions during the assay such as the volume of solutions containing the larvae to be tested (100–250 mL) and their concentration (number of larvae per mL) [ 175 , 224 , 231 , 238 , 239 , 240 ]. In addition, some studies report the use of first and second instar larvae in the test even though late third and young fourth instar larvae are recommended [ 241 , 242 , 243 , 244 ].…”