▎ 摘　　要

Nitrogen doped graphene quantum dots (N-GQDs) have been fabricated using lemon juice by a simple and cost effective thermal pyrolysis technique, without the consumption of any harmful chemicals or solvents. N-GQDs displayed excellent water solubility, good stability and excitation dependent down conversion fluorescence (FL). The obtained N-GQDs displayed a strong FL emission at wavelength around 440 nm at optimum excitation wavelength of 340 nm. FL spectrum of N-GQDs showed highly selective and sensitive quenching with the addition of 2,4,6-trinitrophenol (TNP). The calibration curve from Stern Volmer equation showed a linear range from 0 - 4 mu M with obtained detection limit of 420 nM. This work demonstrated simple, green and facile synthesis of N-GQDs and the obtained N-GQDs were successfully applied for the detection of mutagenic water pollutant, TNP. (C) 2017 Elsevier B.V. All rights reserved.