The Preparation Of Fluor Escence Carbon Nanomaterials Based On Thiol-ene Click Reaction And Their Biological Application

The traditional fluorescent nanomaterials possess their inherent disadvantages(biotoxicity and photobleaching),which limit their further practical applications.Therefore,new fluorescent nanomaterials with excellent biological and optical properties need to be prepared.Fortunately,due to their high fluorescence stability and excellent biocompatibility,fluorescent carbon nanomaterials are considered to be one of the best alternatives to traditional fluorescence.Based on these advantages,fluorescent carbon nanomaterials have become one of the most active research hotspot in the fields of optoelectronic devices,biomarkers,biosensors and biological imaging.However,the common preparation methods of fluorescent carbon nanomaterials need harsh reaction condition and don’t possess universality for most carbon nanomaterials.Thus,it is still urgent to develop efficient preparation methods for fluorescent carbon nanomaterials.In this paper,we proposed a universal method for the preparation of fluorescent carbon nanomaterials,based on the thiol-ene click reaction.Three kinds of fluorescent carbon nanomaterials(graphene quantum dots,fluorescent nanodiamond and fluorescent fullerene)have been prepared efficiently.The main achievements are presented as the following:(1)Based graphene oxide as raw materials,a large-scale preparation method of graphene quantum dots was proposed by thiol-ene click reaction.In addition,graphene quantum dots possess many excellent properties,such as uniform nanometer size,bright green fluorescence and stable optical stability.Further biological evaluation demonstrated their great biocompatibility and the ability of biological imaging.Therefore,the preparation of graphene quantum dots with excellent performance through one-step chemical reaction have high potential for biomedical applications.(2)The polyethylene glycol with thiol(PEG-SH)was prepared,which is modified on the surface of nanodiamond by the thiol-ene click reaction,and the nanodiamond material with blue fluorescence was prepared via one-step reaction.The modification of PEG-SH also endows nanodiamond with great water dispersion and extremely low cytotoxicity,which also makes it possess a rosy prospect for biological imaging.(3)Based on thiol-ene click reaction,carboxylic fluorescent fullerenes were synthesized.A large number of carboxyl functional groups can improve the water dispersion and biocompatibility of fullerenes.In addition,carboxyl functional groups can conjugate drug molecules(cisplatin)to achieve pH responsive release of the cisplatin drugs.This system integrates biological imaging and controlled release of drugs,and is dedicated to the theranostic.