Fluorescence-based detection of mercury ions using carbon dots: role of synthesis route
Shivanand H. Nannuri, Simranjit Singh, Santhosh Chidangil, Sajan D. George
Abstract
This work demonstrates the significance of the synthesis routes, namely microwave and hydrothermal methods, of green-emitting carbon dots prepared from the same precursors in the selective detection of Hg2+ ions. Aside from providing the advantage of a shorter time scale for the synthesis of C-dots (5 min) compared to the hydrothermal route (8 h) at a synthesis temperature of 180°C, the C-dots prepared via the microwave synthesis route exhibit higher absolute quantum yield (1.8 times) while retaining similar pH and concentration-dependent emission properties. Due to the difference in surface nitrogen content, the microwave synthesized C-dot fluorescence emission exhibit a linear behavior from 8 nM to 64 nM of Hg2+ ions and provides a limit of detection of 3.09 nM whereas hydrothermally synthesized particles exhibit linear variation from 0.5 µM to 4 µM with a detection limit of 0.22 µM .