Fluorescent carbon dots for glyphosate determination based on fluorescence resonance energy transfer and logic gate operation

- An “AND” logic gate and specific fluorescence switch sensor for sensitively sensing glyphosate is established.
- The validity was verified by comparing the results with other methods and the detection limit is 0.6 μmol L−1, which is lower than for most of the recently published methods.
- The mechanism of fluorescence resonance energy transfer (FRES) is discussed thoroughly.

Herein, a novel method based on fluorescence resonance energy transfer (FRET) between carbon dots (CDs) and glyphosate (Gly) was designed for Gly detection. CDs were synthesized via a facile and one-step hydrothermal method using citric acid and Tris. The CDs possessed strong blue fluorescence and excitation wavelength-dependent emission behavior with the maximum excitation and emission wavelength at 340 nm and 410 nm, respectively. However, the presence of glyphosate could effectively quench the fluorescence intensity of the CDs through FRET and this phenomenon has been exploited to design an “AND” logic gate for sensitively sensing Gly for the first time. Furthermore, the proposed method has been successfully utilized to detect glyphosate in water samples with satisfactory results. The detection limit for glyphosate was 0.6 μmol L−1(3σ/k), with the linear range of 0.02-2.0 μmol L−1. This is a promising approach for rapid screening of glyphosate in environmental water samples without using any costly instruments.

142An specific fluorescence switch sensor was designed for sensing glyphosate (Gly) based on the fluorescence resonance energy transfer.