Targeting cancer cells through iron(III) complexes of di(picolyl)amine modified silica core-shell nanospheres

► The Fe(III)-di(picolyl)amine complex modified nanospheres displayed enhanced HeLa cells uptake in vitro. ► This is the first report of a multifunctional nanosphere that combines the advantage of a target of cancer environment and fluorescence imaging. ► The conjugate of dpa-Fe(III) complex and fluorescence core-shell nanoparticles RBITC-SiO2 represents a class of novel multi-functional nanoparticles.