Study On Fluorescent Carbon Nanoparticles Modified By Environmental-responsive Polymers And Their Properties

Fluorescent carbon nanoparticles have good biocompatibility,low toxicity and optical stability.They are favored by researchers in the fields of sensing,bio-imaging and drug release.In this paper,fluorescent carbon nanoparticles were modified by RAFT?reversible addition-fragmentation chain transfer polymerization?method,and their applications in analytical sensing were studied.The main contents are as follows:1.A series of fluorescent carbon nanoparticles grafted on the surface of poly AAPBA?f-CNPs-g-poly?AAPBA??were prepared by RAFT method.Both glucose and sucrose have the ability to quench the fluorescence of f-CNPs-g-poly?AAPBA?,and the quenching ability of the same concentration of glucose or sucrose to the fluorescence of f-CNPs-g-poly?AAPBA?becomes stronger with the decrease of the length of the graft chain.When the concentration of glucose or sucrose is 0-1?M,there is a good linear relationship between the fluorescence intensity of f-CNPs-g-poly?AAPBA?and the concentration of glucose or sucrose.Therefore,in the range of 0-1?M,the hybrid material can be used for the quantitative determination of glucose or sucrose.2.The copolymers of acrylamide phenylborate?AAPBA?and fluorescein?AF?were grafted on the surface of fluorescent carbon nanoparticles by RAFT method.The double emission fluorescence of f-CNPs-g-poly?AAPBA-co-AF?has a good response to the change of pH in the range of pH 9.04-12.19.The results show that the f-CNPs-g-poly?AAPBA-co-AF?hybrid material has a good response to the change of pH in the range of 9.04 and 12.19.There was a good linear relationship between the ratio of fluorescence intensity of fluorescein and carbon point and pH value.At the same time,the fluorescence of Cu²⁺,Fe³⁺and glucose was quenched obviously.In the concentration range of0.005-1?M,the fluorescence intensity of the fluorescein and the concentration of Cu²⁺have a good linear relationship,and the fluorescence intensity of the fluorescein is well linear with the concentration of the Fe³⁺and the glucose in the concentration range of 0.01-1?M.3.The copolymer of acrylamide phenylboric acid and acrylamide propanediol?AAMPO?was grafted onto the surface of fluorescent carbon nanoparticles by RAFT method,and the ratio of AAPBA and AAMPO monomer was changed.A series of hybrid materials with different pH response ranges were prepared.With the increase of the ratio of AAMPO in the grafted polymer,the pH response range of the graft polymer is also increasing.No matter the ratio of AAPBA to AAMPO in the grafted polymer,the fluorescence intensity and pH value of the grafted polymer have a good linear relationship,and the linear correlation constants are above 0.99.4.The f-CNPs-g-poly?AAPBA-co-AAMPO?-b-PAF hybrid materials were prepared by grafting block copolymers of acrylamide,acrylamide and fluorescein on the surface of fluorescent carbon nanoparticles by RAFT.The f-CNPs-g-poly?AAPBA-co-AAMPO?-b-PAF hybrid materials were obtained by grafting block copolymers of acrylamide,acrylamide and fluorescein on the surface of fluorescent carbon nanoparticles.The double emission fluorescence has good responsiveness in the range of pH 9.56-13.10,and the ratio of fluorescence intensity of fluorescein to carbon point has a good linear relationship with pH value.In addition,both Hg²⁺ and Fe³⁺ have the ability to quench the fluorescence of the hybrid material.The fluorescence intensity of the hybrid material has a good linear relationship with the concentration of Hg²⁺and Fe³⁺in the range of 0.01-1?M.