The polymers that change their properties in response to external environmental conditions are termed smart polymers. Smart polymers are also known as stimuli-responsive or environmentsensitive polymers and have been used widely in the area of biotechnology, pharmaceuticals, biomedicals, and bioengineering. Polysaccharide-based cross-linked networks are one of the most important classes of nanocomposites and have got signiicant applications. Contamination of water by industrial efluents such as heavy metal ions, dyes, and polyaromatic molecules is one of the most serious environmental issues and has adverse effects on human health. Water pollution has become the major source of

concern and a priority for most of the industries. For last few years, scientists from all over the world are working on the removal of toxic pollutants from the polluted water, and adsorption is one of the most preferred methods. Natural polysaccharides and their derivativesbased cross-linked nanocomposites are known to be one of the best absorbents and the method is a low cost green technology.