Synthesis,characterization And Applications Of Nitrogen-doped Fluorescent Carbon Nanomaterials

Fluorescent carbon nanomaterials(FCNs)have shown a wide range of applications in many fields such as bioimaging,detection of heavy metal ions,detection of biomolecules,and optoelectronic materials.In this paper,several FCNs with high fluorescence quantum yield and good water-solubility were prepared and applied to the detection of mercury ions,L-cysteine,iodine ions and hypochlorous acid.The main contents are as follows:(1)The nitrogen-doped carbon quantum dots(N-CQDs)were prepared from tartaric acid,citric acid and ethylenediamine by one-pot solvothermal method in oleic acid media.The product was characterized by transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),elemental analysis,fluorescence and ultraviolet spectra,and so on.The results showed that the N-CQDs with fluorescence quantum yields(QYs)up to 42.0 % had uniform size.The products had good water-solubility,and were applied to the detection of mercury ions,cysteine and iodine ions by fluorescence "off-on" way.(2)The above-mentioned N-CQDs were also applied to the detection of hypochlorous acid by fluorescence "turn-off" way.The method exhibited high selectivity and sensitivity.The fluorescence of the N-CQDs can be quenched by about 95 % with the addition of hypochlorite.The linear response range of hypochlorite was from 0 to 27 ?M with a detection limit of 29.7 n M.(3)The fluorescent carbon nitride nanoparticles(CNNPs)were prepared from tartaric acid and urea by one-step solvothermal method in oleic acid media.The obtained CNNPs was characterized by transmission electron microscope(TEM),elemental analysis,X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectra(FTIR),X-ray diffraction spectra(XRD),fluorescence and ultraviolet spectra,and so on.The CNNPs with fluorescence quantum yield up to 17.9 % possessed crosslinked structure.The CNNPs were applied to the detection of hypochlorous acid by fluorescence "turn-off" way.The linear response range of hypochlorite was from 0 to 30 ?M with a detection limit of 13.0 nM.