Sensitive and selective fluorescent chemosensor for the detection of some organophosphorus pesticides using luminescent Eu(III) complex

• This is an interesting application for the detection of trace amount of pesticides.
• The detection limits for pesticides are calculated.
• The binding constants and thermodynamic parameters were evaluated.
• Effect of other pesticides on the luminescent probe has been investigated.

A new luminescent europium-o-(4-methoxy benzoyl) benzoic acid [o-(4-anisoyl)] complex in ethanol–water (5:5 v/v) solution was used for selective determination of organophosphorus pesticides. The interaction of new and selective luminescent europium complex with different pesticides was studied using electroanalytical methods and fluorescence technique. The results indicate that the pesticides azinphos ethyl, chlorfenvinphos, diazinon and isofenphos, exhibit quenching effect on the characteristics emission peak for Eu(III) at λ = 614 nm. The luminescence variations values using the probe Eu-(o-(4-anisoyl))2 fit Stern–Volmer equation, where the detection limits are 1.93, 2.82, 3.78 and 1.80 μmol L−1 for azinphos ethyl, chlorfenvinphos, diazinon and isofenphos, respectively. The binding constants at different temperatures were calculated. Also, it was found that the quenching mechanism is dynamic type for chlorfenvinphos, diazinon and isofenphos while static type for azinphos ethyl. Effect of some relevant interferents on the detection of pesticides has been investigated.

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