Application Of Metal/non-metal Hybrid Carbon Dots In Analytical Detection And Photothermal Therapy Of Tumors

Carbon quantum dots(CQDs)are new types of quasi-zero-dimensional carbon nanomaterials with spherical structures.CQDs are endowed many excellent properties by the abundant functional groups on the surface,such as excellent fluorescence performance,easy functionalization,good biocompatibility,environmental friendliness,etc.,making it shows broad application prospects in the fields of photothermal therapy,bioimaging,environmental water quality testing,anti-counterfeiting,catalysis and other fields.In this thesis,two kinds of doping fluorescent CQDs were prepared by one-step hydrothermal method,and the optical properties of the CQDs were characterized in detail.The prepared CQDs were used for drug detection,cell imaging and photothermal antitumor therapy.The main contents of the research are as follows:Chapter 1:The structure and physical and chemical properties of the CQDs were summarized.Summarizing the metal and/or non-metal doped CQDs.The application research of the CQDs in the fields of drug analysis and detection,photothermal anti-tumor therapy,photoelectricity and anti-counterfeiting were summarized.Chapter 2:In the chapter,3-aminothiophenol was used as the reaction precursor,and nitrogen and sulfur co-doped carbon quantum dots(N,S-CQDs)were prepared by a one-step hydrothermal carbonization method.The structure and spectral properties of the N,S-CQDs were characterized in detail by element analysis,high-resolution transmission electron microscopy,fourier transform infrared spectroscopy,ultraviolet-visible absorption spectroscopy,and fluorescence spectroscopy.Because of electrostatic interaction between azithromycin(AZM)and N,S-CQDs,and the cooperative static quenching effect effectively quenches the fluorescence of N,S-CQDs,a fluorescent probe for the rapid detection of AZM was constructed.The probe is not only non-interfered by amino acids and drugs,but also has high selectivity and good sensitivity.The N,S-CQDs can be used for the detection of AZM in the linear ranges of 2.5?32.3?M and 37.2?110?M with the detection limit of 1.80?M.The fluorescent probe has been successfully used for the detection of AZM in actual drugs and urine samples of healthy people.The recovery rate and relative standard deviation of the standard addition are98.2?104.8%and 0.04?3.46%,respectively.The detection results were confirmed by the HPLC-UV standard method.The research results confirmed that the N,S-CQDs as a fluorescent probes is feasible for the detection of AZM in actual drugs and urine samples,and the detection results are reproducible.So the N,S-CQDs is expected to be used for drug supervision.Chapter 3:In this chapter,3-aminothiophenol and AuCl₃were used as reaction precursors to prepare gold-doped carbon quantum dots(AuCQDs)through a one-step hydrothermal carbonization method.The fluorescence quantum yield of AuCQDs(52.634%)is 4.4 times that of the undoped carbon dots(N,S-CQDs),indicating that the doping of trace gold into AuCQDs significantly improved the luminescence performance of the CQDs.There is an electrostatic interaction between folic acid(VB9)and AuCQDs.At the same time,VB9 maked the fluorescence of AuCQDs sharply weakened by static quenching,so a fluorescent probe for detecting VB9 was constructed.The linear range of detection is 1.0?10.9?M and 10.9?91.7?M,and the detection limit is 125.7 n M.It has been successfully used for the detection of VB9 in cells,actual drugs and urine samples.Chapter 4:Gold-doped nanomaterials can be used as photothermal reagents for photothermal anti-tumor therapy.Based on the prepared gold-doped carbon dots(AuCQDs),this chapter studied its use as a photothermal reagent to carry on photothermal anti-tumor therapy in mice.First,the photothermal effect of different concentrations of the AuCQDs(0.01,0.05,0.1,0.5,1.0 mg/m L)was studied.After 808 nm laser irradiation,the maximum temperature of the AuCQDs can reach at 55.1 ?,demonstrating that the AuCQDs has good photothermal conversion effect.Secondly,the temperature of the AuCQDs(1.0 mg/m L)remained unchanged after six rounds of laser irradiation,indicating that the AuCQDs has strong photothermal stability.Moreover,the AuCQDs also has low cytotoxicity and good biological compatibility.Therefore,the AuCQDs was proved to be an ideal photothermal conversion reagent.More importantly,the photothermal conversion ability of the AuCQDs was verified in mice.The results showed that the tumors of the mices had been significantly reduced by treating with the AuCQDs under 808 nm laser irradiation.Therefore,the AuCQDs was proved to have good photothermal anti-tumor effect,indicating that the AuCQDs has potential application prospects in the field of photothermal anti-tumor therapy.