Property And Application Study Of Fluorescent Carbon Dots Discovered In Beverages

Shortcomings of traditional organic fluorescent dyes,such as poor light stability,easy quenching and poor biocompatibility,bring a lot of questions to the application work.Therefore finding a new type of fluorescent material become a tricky task.Recently,fluorescent nanomaterials,such as semiconductor quantum dots and carbon nanoparticles(carbon dots)have been appeared.Although quantum dots have good fluorescence properties,most of them are constituted by toxic heavy metals,they also have the disadvantage of high toxicity and light blinking which limit their use application.Researchers reported surface passivated carbon nanoparticle could emit visible light,creating a new era.Carbon dots compared with organic dyestuff and semiconductor quantum dots have the ability of resistance to photobleaching,high light stability,high biocompatibility,low toxicity,minor injury in cells and they also have an unique advantage for biomarkers in vivo,Carbon dots are expected to replace quantum dots for live cell labeling image and animal vivo image which are arousing the researchers' great interest.Therefore,fluorescent carbon nanoparticles are the ideal biological fluorescent labeling materials which can provide new area for the new luminescent carbon nanoparticle.The main work of this paper wrer as follows:The extract of carbon dots:using column chromatography to extract carbon dots directly from Nescafe?Original instant coffee,coca,pepsi and KbaC as raw materials.Transmission electron microscopy(TEM)image of the C-dots showed that they were roughly spherical particles,good dispersancy in water and the diameter less than 5.0 nm.The emission spectra appeared obvious red shift with the increase of excitation wavelength.The UV-Vis spectrum showed a peak at approximately around 260 nm.to ?-?*transition.The carbon dots of this text conducted cell toxicity and cell labeling experiment.The four kinds of carbon dots had low cell toxicity,no visible reduction of cell viability was found with a concentration as high as 20 mg/mL.The four kinds of carbon dots had good biocompatibility,labeled cells have bright fluorescent wiht diffrernt excitation wavelength.The C-dots from coffee were use to label small animal fluorescent imaging by feeding guppy fish with the diet mixed C-dots.The results showed the coffee carbon dots could enter into fish and emit bright fluorescent.So the coffee carbon dots had potential for in vivo small animal imaging.Cola carbon dots had no acute toxicity and they were almost cleared out from the body after 24 h.Cola carbon dots were absorbed almost in cells of the small intestine and colorectums,assembled in the liver and distributed in heart and brain.