A dual magnetic fluorescent molecularly imprinted polymer sensing probe for simultaneous determination of mefenamic acid and diclofenac in milk

Dual magnetic fluorescent sensing probes were designed and fabricated for the detection of mefenamic acid and diclofenac. The dual probes combined magnetic activated carbon and quantum dots within a molecularly imprinted polymer. The fabrication process was optimized to achieve the best performance, and the resulting dual sensing probes were thoroughly characterized. Under optimal conditions, the fluorescence emissions of the dual probes were linearly quenched by mefenamic acid and diclofenac concentrations from 0.50 to 100 µg L⁻¹, with detection limits of 0.32 µg L⁻¹ for mefenamic acid and 0.40 µg L⁻¹ for diclofenac. The imprinting factors were 13.1 for mefenamic acid and 7.1 for diclofenac. The probes demonstrated high sensitivity toward the target analytes, accurately determining their trace concentrations in milk samples, achieving recoveries from 86.2 to 100.1%, with relative standard deviations below 5.0%. The fabricated nanocomposite MIP sensing probes are highly selective to the target analytes in the presence of other interferences in real samples. The dual sensing probes produced results that were consistent with high-performance liquid chromatography, yet the proposed method is more cost-effective, simpler, and faster.

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