Sir,

For fluoride sensing there are many optical nanoprobes synthesized with good sensitivity and selectivity. These may help..

http://www.sciencedirect.com/science/article/pii/S0003269701954764

http://pubs.acs.org/doi/abs/10.1021/ja036248g

http://pubs.acs.org/doi/abs/10.1021/ol403082p

Thanks for reply for analyzing the fluoride with the help of probe. But, I am willing in treatment of fluoride contaminated water by nanomaterials.

You need to synthesize selective binders such as calixpyrroles or other pyrrole derivatives for fluoride ion binding and load them on to solid nanomaterials for example magnetic nanoparticles etc. If you search on google you may get many such articles.