Carbon dots (C-dots) with multicolour fluorescence feature are presently gaining much importance in the area of bioanalytics and bioimaging due to their biocompatible and strong fluorescent nature. Herein, we report a one-step method for synthesizing multicolour, surface passivated carbon dots using chitosan as a 'greener' source through microwave pyrolysis approach. The present study also deals with the synthesis of chitosan-pDNA (GFP) nanocomplexes for gene delivery applications. Development of such biofriendly imaging agents and nanocarriers has huge diagnostic and therapeutic potential.

This Brief provides a clear insight of the recent advances in the field of cancer theranostics with special emphasis upon nano scale carrier molecules (polymeric, protein and lipid based) and imaging agents (organic and inorganic).