Determination of thiourea based on the reversion of fluorescence quenching of nitrogen doped carbon dots by Hg2+

Herein, a facile and quick strategy to detect thiourea was conducted based on the reversion of fluorescence quenching of nitrogen doped carbon dots (NCDs) by Hg2+. The NCDs with good water solubility and 17% of quantum yield was synthesized by one-step hydrothermal method, using ammonium citrate and dextrin as carbon source and nitrogen source, respectively. The fluorescence of NCDs was obviously quenched by Hg2+ and can be recovered, due to stronger interaction between thiourea and Hg2+. There was a good linear relationship between the recovered fluorescence and the concentration of thiourea within range of 0.90-10.0 mu M and the detection limit for thiourea detection was 0.15 mu M. The as prepared NCDs can be used for determination of thiourea in tap water, lake water and rice flour products, and the spike recoveries were between 91.6 and 108%. (C) 2019 Elsevier B.V. All rights reserved.