Construction And Application Of Polymeric Fluorescent Nanoprobe Based On Photo-induced Metal Free ATRP

The advent of atom transfer radical polymerization（ATRP）provides a simple and efficient method for the design of polymers with specific structures and excellent properties.Conventional ATRP methods require the use of transition metal catalysts.When the resulting macromolecule polymers are used in electronic materials and biopharmaceuticals,residual metal impurities usually affect their performance.Metal-free ATRP is a novel ATRP method that uses organic photocatalysts instead of metal catalysts.It has attracted widespread attention and research in the field of polymers.In this paper,the metal-free ATRP method was used to graft-modify the surface of Eu³⁺doped hydroxyapatite nanorods(HAp-Eu³⁺)to obtain hydrophilic polymer modified hydroxyapatite nanorods,and various physicochemical properties of hydroxyapatite before and after modification were studied.The specific research work of this article is as follows:（1）Polyethylene glycol functionalization on the surface of Eu³⁺doped hydroxyapatite nanomaterials were modified with polyethylene glycol methacrylate（PEGMA）.Firstly,an ATRP initiator containing an alkyl bromide structure was synthesized,and then PEGMA was used as a monomer,PTH was used as an initiator,DMF was used as a solvent,and the polymerization was initiated from the surface of hydroxyapatite nanorods by irradiation with an ultraviolet lamp at 380 nm.（2）Eu³⁺doped hydroxyapatite nanomaterials were grafted with MPC and IA.Firstly,an ATRP initiator with an alkyl bromide structure was synthesized and then copolymerized with MPC and IA monomers.PTH was used as an initiator and DMF was used as solvent to initiate polymerization on the surface of hydroxyapatite nanorods under UV light irradiation at 380 nm.Hydrophilic fluorescent hydroxyapatite nanorods were prepared and their drug carrier application was studied.（3）Fabrication of water dispersible and biocompatible AIE-active fluorescent polymeric nanoparticles through a“one-pot”Mannich reaction.PhE-OH was synthesized according to our previous report with some modifications.Then,PhE-OH was further reacted with paraformaldehyde and 4-arm poly（ethylene glycol）amine through the“one-pot”Mannich reaction.（4）Self-catalyzed photo-initiated RAFT polymerization for fabrication of fluorescent polymeric nanoparticles with aggregation-induced emission feature.Tetraphenylethylene containing AIE-active CTA was first synthesized.Then the AIE-active TPE-poly（St-PEGMA）copolymers were prepared via self-catalyzed photo-initiated RAFT polymerization using styrene and poly（ethylene glycol）monomethyl ether methacrylate as the monomers.