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. 2022 Nov 21;147(23):5462-5469.
doi: 10.1039/d2an01552h.

Ultrasensitive detection of acephate based on carbon quantum dot-mediated fluorescence inner filter effects

Haiqin Li  1 , Rong Deng  1 , Hamed Tavakoli  2 , Xiaochun Li  1 , XiuJun Li  2
Affiliations

Ultrasensitive detection of acephate based on carbon quantum dot-mediated fluorescence inner filter effects

Haiqin Li et al. Analyst. .

Abstract

Acephate is an organophosphorus pesticide (OP) that is widely used to control insects in agricultural fields such as in vegetables and fruits. Toxic OPs can enter human and animal bodies and eventually lead to chronic or acute poisoning. However, traditional enzyme inhibition and colorimetric methods for OPs detection usually require complicated detection procedures and prolonged time and have low detection sensitivity. High-sensitivity monitoring of trace levels of acephate residues is of great significance to food safety and human health. Here, we developed a simple method for ultrasensitive quantitative detection of acephate based on the carbon quantum dot (CQD)-mediated fluorescence inner filter effect (IFE). In this method, the fluorescence from CQDs at 460 nm is quenched by 2,3-diaminophenazine (DAP) and the resulting fluorescence from DAP at 558 nm is through an IFE mechanism between CQDs and DAP, producing ratiometric responses. The ratiometric signal I558/I460 was found to exhibit a linear relationship with the concentration of acephate. The detection limit of this method was 0.052 ppb, which is far lower than the standards for acephate from China and EU in food safety administration. The ratiometric fluorescence sensor was further validated by testing spiked samples of tap water and pear, indicating its great potential for sensitive detection of trace OPs in complex matrixes of real samples.

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Conflict of interest statement

Declaration of Competing Interest

The authors declare the following competing financial interest(s). The authors from TYUT have filed a China Patent Application (No. 202110392652. 4) to protect the IP associated with the technology described in this paper. Other authors declare no competing interest.

Figures

Figure 1.
Figure 1.
Schematic illustration of the principle of sensitive and quantitative detection of acephate based on CQDs-mediated IFE.
Figure 2.
Figure 2.
(a) UV-vis absorbance spectra of OPD and DAP, and the fluorescence spectra of CQDs. (b) Feasibility test of the ratiometric strategy.
Figure 3.
Figure 3.
The effect of Ag+ (a) and OPD (b) on CQDs fluorescence intensity.
Figure 4.
Figure 4.
Optimization of the concentrations of Ag+. (a) Fluorescence spectra caused by different concentrations of Ag+. (b) The fluorescence intensity at 558 nm with the change of the Ag+ concentration. When the concentration of Ag+ wasd 700 μmol/L, the fluorescence enhancement of the DAP was saturated.
Figure 5.
Figure 5.
(a) Fluorescence spectra of concentrations of acephate (0, 5, 10, 20, 50 and 100 ng/mL) measured by the biosensor based on enzyme inhibition combined with IFE effects. (b) Linear plot of ratiometric response I558/I460 versus the logarithm of the concentration of acephate.
Figure 6.
Figure 6.
(a) Fluorescence spectra of the system by spiking varied concentrations of acephate in tap water (20, 50, 100 and 200 ng/mL). (b) Fluorescence spectra of the system by spiking varied concentrations of acephate in pear (0, 23.33, 46.67, and 93.33 ng/mL).
Figure 7.
Figure 7.
Selectivity investigation. Acephate, 100 ng/mL; other interfering agents, 1000 ng/mL.
See this image and copyright information in PMC

References

    1. Boxstael SV, Habib I, Jacxsens L, Vocht MD, Baert L, de Perre EV, Rajkovic A, Lopez-Galvez F, Sampers I, Spanoghe P, Meulenaer BD and Uyttendaele M, Food safety issues in fresh produce: bacterial pathogens, viruses and pesticide residues indicated as major concerns by stakeholders in the fresh produce chain, Food Control, 2013, 32,190–197.
    1. Bakirci GT, Acay DBY, Bakirci F and Otles S, Pesticide residues in fruits and vegetables from the Aegean region, Turkey, Food Chem, 2014, 160, 379–392. - PubMed
    1. Wan L, Wu Y, Ding H and Zhang W, Toxicity, Biodegradation, and Metabolic Fate of Organophosphorus Pesticide Trichlorfon on the Freshwater Algae Chlamydomonas reinhardtii, J. Agr. Food Chem, 2020, 68, 1645–1653. - PubMed
    1. Richardson JR, Chambers HW and Chambers JE, Analysis of the additivity of in vitro inhibition of cholinesterase by mixtures of chlorpyrifos-oxon and azinphos-methyl-oxon, Toxicol. Appl. Pharm, 2001, 172, 128–139. - PubMed
    1. Eddleston M, A Buckley N, Eyer P and Andrew H Dawson, Management of acute organophosphorus pesticide poisoning, The Lancet, 2008,371, 597–607. - PMC - PubMed