Synthesis of Carbon Dots-Ag/ZnO Nanocomposites for Theranostic Applications

A. Sachdev, I. Matai, P. Gopinath
Indian Institute of Technology Roorkee, IN

Keywords: carbon dots, Ag/ZnO nanocomposites, theranostics

Summary:

Carbon dots (CDs) based nanocomposites have been explored for a variety of applications in the recent past. The present study deals with the synthesis of CD-Ag/ZnO fluorescent nanocomposites and further investigating their theranostic potential. Pegylated CDs were prepared by a one–step hydrothermal method, while Ag/ZnO nanocomposites were synthesized by microwave mediated reactions. Finally, the CD-Ag/ZnO nanocomposites were obtained by dropping the CDs solution into Ag/ZnO dispersed solution under overnight stirring conditions at room temperature. A comparison of the absorption spectra of CDs, Ag/ZnO with CD-Ag/ZnO nanocomposites reveals a blue shift in the absorption maxima. The formation of nanocomposites slightly decreased the fluorescence of CDs due to charge transfer process between metal nanocomplexes and CDs. The quantum yield of the CD-Ag/ZnO nanocomposites (5.20%) also decreased compared to CDs (6.73%). Field emission scanning electron microscopy (FE-SEM) images shows an average size of 50 nm. Pegylated CDs depict multicolor fluorescence and could well be used for imaging the cells non-invasively. On the other hand, CD-Ag/ZnO nanocomposites induced apoptosis at a concentration of 100 µg/mL. CD-Ag/ZnO nanocomposites mediate the desired therapeutic effect, meanwhile allowing the real time imaging of cells. Thus development of such nanocomposite has huge theranostic potential.