Development Of Highly Fluorescent Carbonaceous Quantum Dots For Optical Sensing Applications

Abstract

Carbonaceous Quantum Dots (CQDs) are the carbon nanomaterials with sizes newlinebelow 10 nm. After their discovery in 2004, in 2006 another research group observed newlinethem and name them as Carbonaceous Quantum Dots. Carbonaceous Quantum Dots newlinehave gradually inspired extensive research interest because of their tremendous newlinepotential toward a wide variety of technical applications, including electrochemical newlineluminescence and chemiluminescence, bioimaging, bioanalysis, chemical sensor, newlinebiomolecule/drug delivery, photocatalysis, photodynamic therapy, optronic, newlineelectrocatalysis, and so on. Due to their less toxic and biocompatible nature, these are newlinepromising alternatives to semiconductor quantum dots. The presence of various newlinefunctional moieties on the surface of CQDs gives rise to impart biocompatibility and newlinesolubility of CQDs. CQDs are also suitable for modification by doping and newlinefunctionalization with various organic inorganic, organic and biological materials. newlineThe modifications have been done to gain required properties. Carbonaceous quantum newlinedots are classified as carbon dots, Graphitic carbon nitrides and Graphene Quantum newlineDots. Carbon dots and graphene quantum dots recently emerge as superior newlinefluorophores because of their number of key merits such as excellent photostability, newlinesmall size, biocompatibility, highly tunable photoluminescence property, exceptional newlinemultiphoton excitation property, electrochemiluminescence, ease to be functionalized newlinewith biomolecules, and chemical inertness. Carbon dots and Graphene Quantum Dots newlineare structurally different from each other. CDs are quasi-spherical nanoparticles newlineusually lt10 nm in diameter. They can be amorphous or nanocrystalline with sp2 newlinecarbon cluster. In spite of C-dots, fluorescent GQDs are first synthesized by Pan and newlinegroup in 2010 resemble the crystalline structure of single or a few layered graphene. newlineThe shape of most synthesized GQDs is circular or elliptical, although triangular, newlinequadrate and hexagonal GQDs have been synthesized. On the other hand Graphitic newlinecarbon nitride are N