The Application Of Carbon-nanodot In Proteins Recognition And The Construction Of Drug Carriers

Carbon nanodots have been widely used in biomedical analysis and biomedicine due to their good biocompatibility and photoluminescence properties.In this paper,we mainly focus on carbon nanodots as protein sensors and the construction of carriers of anti-tumor drugs:(1)Carbon nanodots are used for protein recognition and fluorescence labeling Protein is the most basic organic matter in the body and the material carrier of all life activities.Its main function is to maintain the normal metabolism of the body and the transportation of various substances in the body.Proteins are closely related to the activities of living organisms.Therefore,it is necessary to search for a fast,accurate,efficient and maneuverable protein probe in the urgent development of medical diagnosis.In this paper,we synthesised a variety of ultra-small fluorescent carbon nanoprobes by bottom-up method for protein analysis,including two aspects 1)carbon nanodots sensor arrays are used for qualitative identification of various proteins;(2)fluorescent carbon nanodots are used for protein structure sensing and construction of protein fluorescent targeting probes.1)The biosensor receptor arrays were constructed by synthesizing carbon nanodots with different ?-cyclodextrin groups.Proteins were recognized and detected by combining principal component analysis.The result is that this sensor array has a very low detection limit(50?M)with a high sensitivity.In addition,it has good anti-interference and high accuracy in simulated microenvironment,such as blood and urine.To sum up,a new,rapid,efficient and qualitative analysis method for protein could be developed for basic protein research.2)The structure change of hemoproteins ?-helix was monitored in real time by synthesizing non-chiral fluorescent carbon nanodots.The effects of temperature,ROS and other stimulating factors on the structural change of could be reflected by the changes of fluorescence internal filtration effect between carbon nanodots and the hemoproteins.In comparition of the structure information between fluorescence spectrum and circular dichroism:1)fluorescence spectra and circular dichroism showed a high degree of consistency and correlation,correlation coefficient up to 96.1 %;2)The sensitivity of fluorescence analysis to the monitoring of changes in the structure of protein ?-helix was increased by 1000 times than that of circular dichroism.In addition,further to design of the carbon nanodots the performance,it can be used in the application research of protein targeting in organisms.Specifically,carbon nanodots are used as biological probes to actively target the biofilm protein which is overexpressed by nerve cells,capturing the cell pathway factors,and reflecting the over-expression degree of the protein,and further to estimate the disease process in fluorescence changes,thus reflecting the degree of neurodegenerative disease and the degree of treatment and the level of drug screening.(2)Preparation and properties of carbon nanodots/polymer micelle electrostatic self-assemblyNitric oxide(NO)as a gas anticancer drug has been widely reported in recent years.However,some problems such as small molecule pharmacokinetics,high clearance rate and difficult enrichment may occur in the treatment of tumors with this emerging gas drug.Research on the construction of anti-tumor drug carrier for tumor therapy based on the drug loading of NO gas with carbon nanodots.In this paper,we designed an endogenous release of NO carbon nanodots and its electrostatic selfassembly for the study of tumor therapy.Herein,the diblock copolymer m-PEG-b-PASP was prepared by ring-opening polymerization,which was combined with endogenous carbon nanodots through electrostatic interaction to form an electrostatic self-assembly.This electrostatic self-assembly can specifically respond to the stimulation of a limited NO nanometer microbubble in a tumor microenvironment.When the accumulation of nano-bubbles breaks through the three-dimensional limitation of the polymer,it can not only achieve the effect of sudden release to kill tumor cells,but also reduce the drug resistance to drug-resistant cells to a certain extent,thus achieving a synergistic therapeutic effect.This method can improve the phagocytosis rate of various tumor cells to anticancer drugs and reduce the anti-drug resistance in the treatment process to some extent.It also has some synergistic effect in the treatment of pancreatic cancer.In conclusion,this paper based on the ultra-small particle fluorescence carbon nanodots has high value in analysis and detection,specifically as target protein fluorescence probe,and tumor treatment,which provides a new area for the research of ultra-small fluorescent nanoparticles in biomedical applications.