Poly(allylamine hydrochloride)-dextran microgels functionalized with magnetic and luminescent nanoparticles

Microgels of chemically cross-linked poly(allylamine hydrochloride) (PAH) and dextran (named PAH-D) encapsulated with magnetic Fe3O4 and luminescent CdTe nanoparticles were successfully fabricated. The superparamagnetic Fe3O4 nanoparticles were firstly incorporated into PAH-D microgels by in situ synthesis of Fe3O4 nanoparticles in the presence of PAH-D microgels. CdTe nanocrystals with different emissions were then covalently attached to Fe3O4-functionalized PAH-D microgels through the coupling reaction of amine groups of PAH-D and carboxyl groups of CdTe nanocrystals. The successful fabrication of PAH-D microgels functionalized with Fe3O4 and CdTe nanoparticles (Fe3O4&CdTe@PAH-D) was verified by the luminescence of the microgels and their simultaneous manipulation by an external magnetic field. Fe3O4&CdTe@PAH-D microgels have the capability to load a model drug, methyl orange, and release it in a sustainable way because of free amine groups in the corresponding PAH-D microgels. The magnetic and luminescent PAH-D microgels with loading capacity are expected to be widely useful as carriers for magnetic separation and drug delivery followed by luminescent detection.