Bimetallic lanthanide metal–organic framework supported ratiometric molecularly imprinted fluorescence sensor: An innovation for selective and visual detection of dimethyl phthalate

Dimethyl phthalate (DMP) is a prototypical member of the phthalic acid ester class of plasticizers that may remain in food, posing a considerable risk to both food safety and human health. An innovative ratiometric fluorescence sensor (MIPs@BL-MOF) was constructed by incorporating bimetallic lanthanide terbium/europium metal-organic framework (BL-MOF) into molecularly imprinted polymers (MIPs) for the rapid selective and visual detection of DMP. In this work, BL-MOF prepared by the ‘post-mixing’ strategy was intelligently incorporated in the MIPs layer, giving the sensor the ability of rapid mass transfer, efficient binding, excellent anti-interference, and high selectivity. Based on the photoelectron transfer mechanism, high-affinity detection of DMP was realized by MIPs@BL-MOF with a good linear fitting (R² = 0.9944) and theoretical detection limit of 3.29 nmol L⁻¹ in the range of 1.0 × 10⁻⁸-1.0 × 10⁻³ mol L⁻¹. More importantly, a portable visual sensing platform integrated by the MIPs@BL-MOF sensor and smartphone was successfully applied to DMP detection. Accordingly, the MIPs@BL-MOF-based ratiometric fluorescence sensing platform with desirable specificity, sensitivity, and portability holds great potential for the rapid and visual detection of plasticizers for ensuring environmental and food safety.