Synthesis of Nitrogen-Doped Carbon Dots from Nanocrystalline Cellulose by Pyrolysis Method as Hg2+ Detector

Abstract

The synthesis of modified carbon dots (N-CDs) from nanocrystalline cellulose, as the carbon source, with the combination of urea and ethylenediamine, as nitrogen dopant agents, was successfully carried out by pyrolysis at 300°C. The N-CDs dispersed in both ethanol and distilled water generated bright blue fluorescent color under a UV lamp at 365 nm wavelength with a 29% quantum yield value. FTIR analysis confirmed that the surfaces of carbon dots were modified by amine and N-doped groups on the carbon ring structure and the data from the UV-VIS spectrum also showed that assumption. Produced N-CDs had a size distribution of 2-5 nm with an average diameter of around 3.4 nm. The ability of N-CDs as a detector was explored from the fluorescence quenching by Hg2+ ions, in which it reached 40%. The determination of Hg2+ could be completed in 10 min with a wide linearity range from 0-100 µM and a detection limit of 59 µM by the static quenching process.

Keywords

• carbon dots
• metal ion sensor
• nanocrystalline cellulose
• n-dopant agent
• static quenching