Eco-friendly-synthesized chitosan-zinc oxide-selenium nanocomposites: characterization and insecticidal activity

Area of Science:

• Materials Science
• Environmental Science
• Entomology

Background:

• Mosquitoes like Culex pipiens are significant disease vectors.
• Developing eco-friendly and effective vector control agents is crucial.
• Nanocomposites offer novel properties for various applications, including pest control.

Purpose of the Study:

• To synthesize and characterize chitosan-zinc oxide-selenium nanocomposites (Ch-ZnO-Se NCs).
• To evaluate the larvicidal and adulticidal efficacy of Ch-ZnO-Se NCs against Culex pipiens.
• To investigate the inhibitory effects of Ch-ZnO-Se NCs on key mosquito enzymes.

Main Methods:

• Ch-ZnO-Se NCs were synthesized using chitosan as a reducing and stabilizing agent.
• Nanocomposite characterization involved various analytical techniques, revealing spherical nanoparticles (mean diameter 73.95 nm).
• Larvicidal and adulticidal assays were performed, alongside enzyme activity measurements (GST and AChE) and molecular docking studies.

Main Results:

• Ch-ZnO-Se NCs demonstrated significant larvicidal and adulticidal activity against Culex pipiens, with LC50 values of 23.308 μg/ml and 57.167 μg/ml, and LC90 values of 30.632 μg/ml and 52.063 μg/ml, respectively.
• Larval mortality reached 100% at 60 μg/ml, and adult mortality reached 97.33%.
• Exposure to Ch-ZnO-Se NCs increased glutathione S-transferase (GST) activity and decreased acetylcholinesterase (AChE) activity, consistent with molecular docking results showing strong binding affinities.

Conclusions:

• The synthesized Ch-ZnO-Se NCs are effective and eco-friendly agents for controlling Culex pipiens.
• These nanocomposites show potential as inhibitors of mosquito enzymes AChE and GST.
• The findings suggest Ch-ZnO-Se NCs as promising candidates for novel vector control strategies.