Fluorescence Carbon Dot-based Imprinted Polymer for Highly Selective Detection of Bovine Hemoglobin / 分析化学

A novel fluorescent imprinted polymer (CDs@ MIP) with selective recognition of hemoglobin was prepared by the sol-gel method using fluorescent carbon dots as the carrier material, 3-aminopropyltrieth-oxysilane as the functional monomer, tetraethoxysilane as the crosslinking agent and bovine hemoglobin as template molecule. The results of IR and scanning electron microscopy showed that the molecularly imprinted polymer was coated on the surface of fluorescent carbon dots. The CDs@ MIP showed selective recognition properties for bovine hemoglobin with an imprinting factor of 4. 60. Also the adsorption ability and specific recognition performance of CDs@ MIP were investigated, and it was found that the CDs@ MIP had high selectivity toward bovine hemoglobin, and the selection factors for ovalbumin, bovine serum albumin and human serum albumin were 4. 38, 4. 73 and 3. 66, respectively. Under the optimal conditions, the linear range of CDs@ MIP for bovine hemoglobin was 0. 1-10. 0 μmol/ L and the detection limit was 23. 0 nmol/ L. The CDs@ MIP was successfully used for the determination of bovine hemoglobin in bovine blood samples with recoveries of 99. 0％ -102. 5％ .

Transmembrane mechanism and intracellular trafficking of folic acid-polyethyleneimine carbon dots / 吉林大学学报(医学版)

Objective:To investigate the transport pathway and intracellular distribution of the of fluorescent carbon dots(CDs)synthesized by folic acid and polyethyleneimine(PEI)through the membrane of MC3T3-E1 cells and its effect on the cells,and to clarify the mechanism.Methods:The fluorescent CDs with the function of cell imaging were synthesized by hydrothermal method using folic acid and PEI as the raw materials;MTT assay was applied to screen the best concentration of CDs.The MC3T3-E1 cells were divided into blank control group,folic acid group and CDs group.The biocompatibility of CDs was evaluated by the detection of cell cycle,apoptosis and cellular reactive oxygen species(ROS)level.Nystatin as a kind of caveolae inhibitor and nocodazole as a kind of macropinocytosis inhibitor were used to find out the pathway through which the cells took in the CDs.Using the charcteristic of CDs with blue fluorescence stimulated by ultraviolet ray,the organelle probes were used to observe the distribution of CDs.Results:Compared with blank control group,the cells in different concentrations(100-450 mg·L-1)of CDs groups showed no cytotoxicity at 24 h(P>0.05);at 48 h,the cell proliferation rate was reduced to 68.4% of blank control group when the concentration of CDs reached 350 mg · L -1(P<0.05). Compared with blank control group,the percentages of cells in G0phase and G1phase in CDs group were decreased (P<0.05),and the percentage of cells in S phase was increased(P<0.05);the percentages of cells in G2phase and M phase were increased,but there no was significant differences(P>0.05).Compared with blank control group,the apoptotic rates of the cells in folic acid group and CDs group had no significant differences(P>0.05). Compared with blank control group,the intracellular ROS levels in folic acid group and CDs group were significantly decreased(P<0.05).Compared with blank control group,the uptake amount of CDs in the cells was decreased in nystatin group(P<0.05).The blue fluorescence of CDs overlapped with the red fluorescence of mitochondria under an inverted fluorescence microscope,the blue fluorescence of CDs overlapped with the red fluorescence of lysosomes;they didn't overlap completely with the red fluorescence of the endoplasmic reticulum;the blue fluorescence of CDs overlapped poorly with the red fluorescence of Golgi apparatus.Conclusion:CDs perform well in biocompatibility and they can be distributed to different organelles after taken in by the cells.They can be used as a kind of gene carrier in transgenic therapy.

Preparation of Element-doped Fluorescent Carbon Dots and Their Applications in Biological Imaging / 分析化学

Carbon dots have drawn a lot of attentions for their potential usage in bioimaging on the basis of their good biocompatibility and excellent anti-photobleaching ability. However, the relative low fluorescence quantum yield and lockage of near infrared fluorescence emission restrict their applications in the fluorescence imaging analysis. With the improvement of fluorescent properties through different elements doping, more and more carbon dots are used in biological imaging. In this paper, the synthesis of element-doped carbon dots, the influence by different elements doping and the development of element-doped carbon dots in imaging analysis are summarized, and the future prospect are anticipated.