Abstract: Highly fluorescent carbon nanoparticles (FCNs), with tunable emission colours of particle size between 1-10 nm also stable in solid form with high quantum yield (>5%) and its method of synthesis thereof yielding said carbon nanoparticles in milligram to gram scale in high synthesis yield (>80%). The present invention also provides for highly fluorescent carbon nanoparticle solution doped with heteroatom (such as oxygen, nitrogen) and its method of synthesis favoring yield of the said doped carbon nanoparticles of even smaller size ranging from 1-5 nm with narrow size distribution, and also provides for functionalized FCNs that are non-toxic, functional, soluble and stable fluorescent carbon nanoparticles with retained fluorescence for variety of end uses in biomedics, imaging applications, and detection techniques.

Abstract: The present invention deals with transition metal ions doped semiconductor nanocrystals that are free from heavy metals like cadmium and therefore environment friendly and useful for biological applications. The present invention also describes a process for the preparation of such transition metal ion doped semiconductor nanocrystals, where the reactions take place at a temperature less than 3000 C. The said doped nanocrystals are stable in air and under UV radiation in both solution and precipitated solid form.