Surface passivation of carbon nanoparticles with p-phenylenediamine towards photoluminescent carbon dots

The versatility of the surface chemistry of carbon dots (CDs) can generate high flexibility in engineering their surface functionality for a wide and precise array of applications. In respect of this, we perform for the first time the surface passivation of carboxylated carbon nanoparticles with p -phenylenediamine to prepare water soluble photoluminescent CDs exhibiting intriguing physicochemical properties. The new strategy used to engineer the surface functionality allows us to synthesize CDs with a stable excitation independent green photoluminescence with a quantum yield of 14% and lifetime of 11.8 ns, suitable for application in bioimaging, sensing and optoelectronics. New photoluminescent carbon dots with intriguing photoluminescent properties were prepared from carboxylated carbon nanoparticles via covalent bonding of p -phenylenediamine oligomers.