Preparation And Surface Modification Of Fluorescence Carbon Nanoparticles

Carbon nanoparticles (CNPs) is one of the new fluorescent carbon nanomaterials. It has smaller particle size, lower toxicity or non-toxic, better biocompatibility, easier to be surface functionalized, more stable fluorescence properties and easier to be prepared. Its emission wavelength can be adjusted also. CNPs has been applied in the field of bioimaging, fluorescence detection, photocatalysis and others due to all these characteristics. In this paper we modified the surface of CNPs and enhanced the fluorescence quantum efficiency successfully. The detail work is as follow:1. CNPs with blue fluorescence was synthesized from glucosamine hydrochloride via a hydrothermal process. The morphology of the CNPs was characterized by transmission electron microscope (TEM). The functional groups on the surface of the CNPs were confirmed through infrared spectrum, and then speculated the possible structure of CNPs on the basis of the mass spectra analysis. The influences on the fluorescence intensity of the CNPs were investigated.2. In order to improve fluorescence quantum yield and fluorescence stability of the CNPs the surface of CNPs had been modified by using phenylalanine. The influence factors including reaction time, pH value, Phe dosage and reaction temperature had been studied. Orthogonal analysis method was employed in this process.3. Further modification of CNPs-Phe had been achieved by using 2,2'-bipyridine-4,4'-dicarboxylic acid to improving fluorescence quantum yield and stability. The effects of reaction time, temperature, dosage of concentrated sulfuric acid and dosage of 2,2'-bipyridine-4,4'-dicarboxylic acid on the interaction between CNPs-Phe and 2,2'-bipyridine-4,4'-dicarboxylic acid had been discussed.