Toxicity Evaluation of Chemically and Plant Derived Silver Nanoparticles on Zebrafish (Danio rerio)

Abstract

Silver is a noble metal with antique values and antimicrobial property. Being its colloidal form, silver nanoparticles have wide commercial application. They are being used extensively in the aquaculture industry. Considering their dum** and leaching in water, experiments were conducted to estimate their toxicity on zebrafish (Danio rerio). Silver nanoparticles were synthesized using sodium borohydrate (chemical synthesis) and Guava (Psidium guajava) leaf-extract (biological synthesis) as reductants. UV–Visible spectroscopy exhibited a confirmatory surface plasmonic range of 390–410 nm and transmission electron microscopy data projected a homogenous, round (11–45 nm) and polygonal (17–40 nm) particles of the silver nanoparticles synthesized in chemical and phyto-synthesis routes respectively. Acute toxicity study of these chemicals was conducted in static bioassay method. 96 h LD₅₀ dose for silver nitrate was 100 μg l⁻¹ where as it was 80 and 400 μg l⁻¹ for chemically and biologically synthesized silver nanoparticles respectively. The calculated safe concentration values in water were 0.020, 0.033 and 0.153 mg l⁻¹ for silver nitrate, chemically synthesized nanoparticles and biologically synthesized silver nanoparticles respectively. These candidate chemicals had not influenced any significant alterations in water quality. Current investigations confer that chemically synthesized silver nanoparticles are more toxic than silver nitrate to zebrafish. Biologically synthesized silver nanoparticles are least toxic among all. These trends of impact were also evaluated and reconfirmed through histological assessment of ovarian tissue at sublethal dose (1/10 th of LD₅₀ value). Thus, the potentiality of plant derived nanoparticles should be investigated in different fish models for their sustainable application in aquaculture and water technology.