Blue-emitting and amphibious metal (Cu, Ni, Pt, Pd) nanodots prepared within supramolecular polymeric micelles for cellular imaging applications

Abstract

We propose a new method for the preparation of blue-emitting and amphibious metal (Cu, Ni, Pt, Pd) nanodots using supramolecular polymeric micelle nanoreactors. The supramolecular polymeric micelles were constructed by electrostatic interactions between hyperbranched poly(ethylenimine)s (HPEI) and palmitic acid (PA). After encapsulation of the metal ions and subsequent reduction by NaBH₄, blue-emitting metal nanodots in chloroform phase were formed. The resulting metal nanodots could be phase transferred from chloroform phase to aqueous phase by adding triethylamine, thus aqueous metal nanodots in the form of metal nanodot/HPEI could be obtained. The aqueous metal nanodot/HPEI exhibited preeminent fluorescence properties for bio-imaging. The fluorescent metal nanodot/HPEI integrates the fluorescence property of metal dots with the gene transfection character of HPEI, indicating an ideal fluorescence probe for tracking gene transfection behaviour.