Rapid growth of nanotechnology in various fields like medicine, diagnostics, biotechnology,
electronics has gifted the world with products having extraordinary benefits. With increasing
use of nanotechnology based products, there is a growing concern about toxicity associated with
nanoparticles. Nano-size attributes unique properties to the material due to the increased surface
area. But toxic effects associated with nanoparticles are also pronounced. Therefore, research in
the field of nanotoxicology is of great importance. Some critical properties of nanoparticles such
as chemical composition, size, shape, surface properties, purity are determinants of nanotoxicity.
Thus, meticulous characterization of nanoparticles prior to toxicity assessment helps in reducing
the toxicity by careful designing of nanoparticles. In vitro assessment of nanotoxicity involves testing
on cultured cells whereas in vivo testing involves use of animal models like mice, rats, aquatic
frogs etc. Use of predictive models like Zebrafish, Drosophila melanogaster for nanotoxicity research
is increased in last few decades. Advanced methods for nanotoxicity assessment involve the
use of electrochemical methods which can also give insights about mechanism of nanotoxicity. As
the literature in this field is dispersed, this review collates various approaches to give a scheme for
nanotoxicity evaluation right from the characterization to toxicity assessment.