Efficient preparation of dual-emission ratiometric fluorescence sensor system based on aptamer-composite and detection of bis(2-ethylhexyl) phthalate in pork

A ratiometric fluorescence sensor system is proposed for detecting bis(2-ethylhexyl) phthalate (DEHP) in pork, which is based on aptamer recognition with molybdenum disulfide quantum dots and cadmium telluride quantum dots (MoS2 QDs/CdTe-Apta). Two signals exist in the system, among which the response signal is transmitted by CdTe-Apta. The amide condensation between aptamers and CdTe QDs shortens the distance between CdTe QDs and DEHP, thus quenching the fluorescence of CdTe QDs, possibly through a photoinduced electron transfer mechanism. The MoS2 QDs deliver the self-calibration signal, and the fluorescence of MoS2 QDs remains almost constant when co-existing with DEHP. Linearity (R2 = 0.9536) was established for the DEHP concentration range 0.005?3.0 mg?L-1, with a limit of detection of 0.21 ?g?L 1. The system was successfully applied in the determination of DEHP in pork. The system has potential for the quantitative determination of DEHP in practical applications.

Automated summary

A ratiometric fluorescence sensor system was proposed for detecting DEHP in pork, using aptamer recognition with MoS2 QDs and CdTe QDs. The system utilizes two signals to transmit response and self-calibration, achieving linear detection of DEHP concentration and successful determination in practical applications.