Fluorescent Carbon Dots from Snake Plant for Applications as Probe for Optical and Electrochemical Sensing of Hg2+ and Fe3+ and Bio-Imaging Agent

Fluorescent carbon dots (CD) have been synthesized from Dracaena trifasciata (snake plant) following a one-step hydro-thermal method and have been characterized on the basis of elemental analysis, XPS, PXRD, TGA, IR, Raman, UV-vis, fluorescence, AFM and HRTEM analysis. The performance of the CDs as probe for the metal ion(s) using optical and electrochemical techniques has been investigated. The fluorescence study suggested that these CDs selectively detect Hg2+ and Fe3+ with detection limits of 13 nM (2.6 ppb) and 12 nM (0.71 ppb), respectively. The electrochemical sensing of Hg2+ and Fe3+ has also been done using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively, using CD coated Glassy Carbon Electrode (GCE) and the LoD value found for Hg2+ is 8 nM (0.45 ppb). The cytotoxicity test revealed that these CDs are non-toxic and the bio-imaging study exhibited that it penetrates into the bacterial and microalgal cell membrane showing good fluorescent image.