Highly efficient fluorescent multi-walled carbon nanotubes functionalized with diamines and amides

A simple and effective method to prepare highly efficient fluorescent multi-walled carbon nanotubes (MWCNTs) is reported. The quantum yield of the as-prepared MWCNTs is up to 0.25, and increases with the shortening of the aliphatic chain of the diamines functionalized on the tubes. The as-prepared MWCNTs have high selectivity for several transition metal ions based on fluorescence quenching which is due to the complexes of tubes and metal ions.