Selective determination of dimethoate via fluorescence resonance energy transfer between carbon dots and a dye-doped molecularly imprinted polymer

• A novel molecularly imprinted fluorescence sensor was fabricated for dimethoate determination.
• Fluorescence sensor was prepared by electrochemical method.
• The FRET system between methyl red and carbon dots was the first studied.
• A kind of new doped molecular template polymer was not only act as the recognize polymer, but also as the donor of FRET system.

A novel molecularly imprinted fluorescent sensor was developed for dimethoate determination based on fluorescence resonance energy transfer. First, a doped molecular template polymer was prepared by electropolymerization. During dimethoate detection, a competitive reaction occurred between dimethoate and carbon dot labeled dimethoate. Fluorescence resonance energy transfer between residual carbon dots labeled dimethoate in the sensor and methyl red on the doped molecularly imprinted polymer then occurred, enhancing the fluorescence signal of the sensor. The fluorescence intensity decreased when the carbon dots labeled dimethoate molecules were replaced by dimethoate molecules in the samples. Under optimal conditions, good linear correlation was obtained for dimethoate over the concentration range from 6 × 10−10 mol/L to 3.4 × 10−8 mol/L with a detected limit of 1.83 × 10−11 mol/L. This sensor was used to detect for dimethoate in actual samples, for which recoveries ranging from 95.0% to 106.0% were obtained.

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