Electrochemical bioplatform for the determination of the most common and carcinogenic dibutyl phthalate migrated from daily-use plastic products.

Dibutyl phthalate (DBP) is a typical plasticizer used in the production and processing of plastic items. Given that DBP is easily leached and discharged into the environment, posing a threat to nature and living things, a facile and feasible impedimetric magneto biosensor for ultrasensitive determination of DBP was constructed first of all by using epoxy-functionalized magnetic nanoparticles as a sensing platform. A magnetic field on the electrode surface kept the epoxy-functionalized magnetic nanoparticles in place, and the particular interaction was conducted on the solid platform of magnetic nanoparticles. This sensing platform with a large surface area enhanced to attach a large amount of DBP-specific aptamer leads to a further increase in the sensitivity of the aptasensor. The DBP-specific aptamer was covalently attached to the epoxy groups of the 3-(glycidoxypropyl)trimethoxysilane (GPMS) agent standing at the magnetic nanoparticle surface without using any crosslinking agent. Meanwhile, the DBP aptamer attached to the as-prepared epoxy-functionalized magnetic nanoparticles via amide bonds specifically recognized the DBP analyte. The interactions of DBP with the aptamer on the epoxy-functionalized magnetic nanoparticles were studied by different electrochemical techniques, and for the quantification of DBP, electrochemical impedance spectroscopy (EIS) was utilized. In the best conditions, the electrochemical aptasensor showed good results for measuring DBP, with a broad range from 1 to 200 pg/mL and a very low detection limit (LOD) of 0.32 pg/mL. Importantly, the resulting aptasensor had excellent repeatability and reproducibility, desirable specificity, long storage stability, and high sensitivity, indicating its potential applications in food and environmental safety. In addition, the real sample experiments performed on the daily-use plastic products revealed the feasibility of the proposed detection approach.