Water soluble fluorescent quantum carbon dots
The present invention relates to the water soluble self fluorescent quantum carbon dots (C-dots). These C-dots are isolated from carbon soot in one embodiment a wax soot solvent washed and isolated from other larger material by filtration such as by membrane filtration. The C-dots can be varied in their color by change of their size and by the amount of oxidative groups' position on each C-dot.
1. A water soluble self-fluorescing quantum carbon dot comprising a carbon dot isolated from carbon soot and treated to produce hydrophilic carboxylic acid groups on the surface of the carbon dot sufficient to cause fluorescence.
2. A composition according to claim 1 which has been bonded to a desired molecule as a fluorescent tag.
3. A composition according to claim 2 wherein the molecule is a part of a bacteria such that the bacteria become tagged.
4. A composition according to claim 2 wherein the molecule is used to tag a cancerous ovary cell line as a fluorescent tag.
5. A composition according to claim 1 wherein the carbon dots have a size of from about 2 nm to about 7 nm.
6. A composition according to claim 1 wherein the carbon dots have been treated by oxidative means to produce hydrophilic carboxylic acid groups on the carbon dot.
7. A composition according to claim 1 wherein the carboxylic acid groups are covalently attached to the surface of the carbon dot without the use of polymeric materials wrapping the carbon dot.
8. A composition according to claim 1 wherein the carbon soot is from a hydrocarbon wax.
9. A method of producing a fluorescent quantum carbon dot comprising
a. heating a hydrocarbon wax to a temperature of between about 500 degree C. and 800 degrees C. under conditions sufficient to produce carbon soot;
b. collecting and purifying the soot to isolate quantum carbon dots;
c. oxidatively treating the quantum carbon dots to remove amorphous carbon and produce hydrophilic carboxylic acid groups on the surface of the dots sufficient to cause the dots to fluoresce.
10. A method according to claim 9 wherein the oxidative treatment is with nitric acid.
11. A method according to claim 9 wherein the purifying is accomplished by solvent washing followed by filtration.
12. A method of tagging a molecule or biological system comprising associating a water soluble self-fluorescing quantum carbon dot with the molecule or biological system.
13. A self-fluorescing hydrocarbon quantum carbon dot functionalized with carboxylic acid groups on the surface of each dot sufficient to cause fluorescence.