Single-shot 'turn-off optical probe for rapid detection of paraoxon-ethyl pesticide on vegetable utilising fluorescence carbon dots

The utilisation of pesticides has become more intensified as to fulfil the demand of food for the ever-growing world population. It leads to the risk of pesticides residues leaching to the environment, which subsequently reflects to the needs of having effective and economical detection and monitoring approach. In view of this, a work has been performed as reported in this paper on the development of a simple and economical single-shot optical probe for the detection of paraoxon-ethyl pesticide on real vegetable samples. The probe adopted carbon dots as sensing receptor that has been synthesised in-house via simple acid carbonisation of sucrose. The carbon dots isolated showed strong yellow fluorescence with the maximum emission at 524nm when excited at 423 nm. Upon edition with paraoxon-ethyl, the emission was quenched accordingly with concentration dependent manner. The sensing protocol was optimised and validated, while the analytical characteristic was evaluated as an effective single-shot probe that can detect paraoxon-ethyl extracted from spiked vegetable leaves. The probe has achieved a limit of detection (LOD) of 0.22 +/- 0.02 mu M and a dynamic linear range up to 5.80 mM. (C) 2016 Elsevier B.V. All rights reserved.