Synthesis,Characterization And Applications Of Fluorescent Carbon Nitride Nano-particles

Fluorescent carbon nitride nanoparticles have been applied in many fields such as biosensing,bioimaging,ion/organic compounds detection and optical devices due to their distinct physical and chemical properties such as low environmental toxicity,high quantum yield,fine chemical resistance and excellent biocompatibility.In this paper,several fluorescence carbon nitride nanoparticles with high quantum yield were prepared from citric acid and three different kinds of nitrogen sources.The fluorescence property,structural characteristic,and detection of metal ions and organic compounds were studied.?1?Carbon nitrogen nanoparticles?CNNPs?with a fluorescence quantum yield of15.2%were prepared from citric acid and melamine in oleic acid medium by a facile microwave-assisted solvothermal method.A new approach for quick,sensitive,and selective determination of 2,4,6-trinitrophenol?TNP?in water was developed based on fluorescence quenching of CNNPs.There exists a good linear correlation?R²=0.9974?between fluorescence quenching and the concentration of TNP in the range of 0 to 50?M.The limit of detection?LOD?was estimated to be 0.11?M based on three times the standard deviation rule.This method can be applied to the determination of TNP in real water samples.?2?Nitrogen-doped carbon nanoparticles?N-CNPs?with a fluorescence quantum yield of 41.5%were prepared from ethylenediamine and citric acid in oleic acid medium by a facile microwave-assisted solvothermal method.Then a new approach for quick and sensitive determination of riboflavin was developed based on fluorescence resonance energy transfer from N-CNPs to riboflavinin.There exists a good linear correlation between fluorescence signal and the concentration of riboflavin in the range of 1 to 20?g·ml^-1.The limit of detection?LOD?was estimated to be 68.5 ng·ml^-1 based on three times the standard deviation rule.This method can be applied to the determination of riboflavin in real samples.?3?Carbon nitrogen nanoparticles quantum dots?CNQDs?with a fluorescence quantum yield of 75.8%were prepared from citric acid and 1,2-diaminobenzene in ol-eic acid medium by a facile microwave-assisted sol-vothermal method.Then a method for the determination of mercuric ions in water was developed based on fluorescence quenching of CNQDs.There exists a good linear correlation?R²=0.9989?between fluorescence quenching and the concentration of Hg²⁺in the range of 0 to 20?M.The limit of detection?LOD?was estimated to be 55 nM based on three times the standard deviation rule.This method can be applied to the determination of Hg²⁺ in real water samples.