One pot synthesis of C-dots and study on its interaction with nano ZnO through fluorescence quenching

Carbon quantum dots (CQDs) are novel fluorescent nanomaterials and elegant building blocks for future nano devices, and have garnered much interest as potential competitors to conventional semiconductor quantum dots. Herein, we report the microwave assisted synthesis of carbon quantum dots of size less than 10 nm and the synthesis of Zinc oxide nanoparticles (ZnO) by combustion method. The synthesized ZnO nanoparticles were characterized by X-ray diffraction, field emission scanning electron microscope and high resolution transmission electron microscope. Due to hazardous effect of ZnO nanoparticles on human health, its detection is important. The fluorescence quenching method has been employed to study the interaction between CQDs and ZnO nanoparticles involving steady state and time resolved measurements at room temperature. The interaction between CQDs and ZnO nanoparticles were studied, due to excellent overlap between the donors' (CQD) emission spectrum and the acceptors' (ZnO nanoparticles) absorption spectrum, Forster's resonance energy transfer theory is applied to measure the distance between the donor and acceptor (r(0) = 5.56 nm) as well as the critical energy transfer distance (R-0 = 55.6 angstrom).