Preparing Multicolor Fluorescence Emission Carbon Dots And Applications In Metal Ion Detection

In recent years,the burgeoning fluorescent carbon dots have shown tremendous potentials for bioimaging and chemosensory applications due to their excellent characteristics such as simple preparation,photostability,low cytotoxicity,tunable fluorescence,good biocompatibility.The tunable multicolor fluorescence emission of carbon dots is a prerequisite for the multi-mode and multi-function application in the bioimage and chemical sensing.However,a few researchers have obtained multicolor emission carbon dots.And there is very little exploration on multiple ion detection.We have obtained multicolor fluorescence emission carbon dots by design experiment and explored its application in the chemical sensing.Specific research contents and results are as follows:Firstly,we prepared carbon dots using m-phenylenediamine（mPD）as the carbon source through solvothermal method.Then,we obtained carbon dots emit red,green and blue three different color with their concentrations changes.Such fluorescence centers of red,green and blue carbon dots exhibited different response patterns for Fe³⁺and Cu²⁺.Red and blue carbon dots can be quenched by Fe³⁺and Cu²⁺,respectively.And the carbon dots emit green color can be enhanced by Fe³⁺.So we obtained fluorescence probe to detect Fe³⁺and Cu²⁺simultaneously.Based on various properties analysis,the fluorescence and detection mechanism of red,green and blue carbon dots were given.Secondly,Aminophenols（three isomers:p-Aminophenol,o-Aminophenol,m-Amino-phenol）are significant carbon source for producing carbon dots by controlling the carbonization process.And the carbon dots emit red,orange,yellow and blue four different color.By means of component properties,the carbon source and carbonization process affected the composition and surface groups of carbon dots,thus changing the fluorescence emission pproperties of carbon dots.Four different fluorescence carbon dots are used for metal ion decetion.The carbon dots emit blue,yellow and orange three different color can be quenched by Fe³⁺.And the carbon dots emit blue color has the strongest quenching,followed yellow and orange fluorescence carbon dots,respectively.In addition,other factors affecting the fluorescence emission of red,orange,yellow and blue carbon dots were discussed.We also have provided possible mechanism for the detection of metal ion.