A novel molecularly imprinted photoelectrochemical aptasensor based on dual recognition mechanism for ultratrace detection of plasticizer dibutyl phthalate

Dibutyl phthalate (DBP) is one of the main phthalate plasticizer pollutants in the environment, which can seriously affect the endocrine and immune systems of animals and plants, and raise the risk of cancer, mutagenesis, reproductive malformation and other diseases. The present work aimed to develop a simple, rapid and ultrasensitive photoelectrochemical (PEC) sensor for DBP detection. By incorporating aptamer recognition mechanism with molecular imprinted technology (MIT), a dual identification strategy was proposed based on metal organic framework (MOF) and Cu2O heterostructure, which was synthesized in situ by electrodeposition and a simple immersion method. Specially, the novel PEC sensor was exploited by controllable selfpolymerization of dopamine with the complex formed by Aptamer [DBP] and DBP incubation on the surface of Cu3(BTC)2/Cu2O/ITO. Owing to the strong light adsorption ability, good stability and enhanced photocurrent of Cu3(BTC)2/Cu2O hybrid under visible light irradiation, and also to the double recognition mechanism of aptamer and MIT, the PEC sensor exhibited highly specific determination of DBP. Under optimal experimental conditions, the designed sensor achieved a linear range from 0.1 pM to 1.0 nM and an extremely low detection limit of 0.035 pM. Moreover, it showed good reliability and practicability in real samples assay. This study extended the development of PEC sensor in plasticizer contaminant detection.

Automated summary

This study aimed to develop a simple, rapid, and highly sensitive photoelectrochemical (PEC) sensor for the detection of dibutyl phthalate (DBP), a major phthalate plasticizer pollutant in the environment. The sensor utilized a dual identification strategy based on a metal organic framework (MOF) and Cu2O heterostructure, incorporating aptamer recognition mechanism with molecular imprinted technology (MIT). The sensor exhibited highly specific determination of DBP due to the strong light adsorption ability and enhanced photocurrent of the Cu3(BTC)2/Cu2O hybrid under visible light irradiation, as well as the double recognition mechanism of aptamer and MIT. The designed sensor achieved a linear range from 0.1 pM to 1.0 nM and an extremely low detection limit of 0.035 pM under optimal experimental conditions, showing good reliability and practicability in real samples assay. This study extends the application of PEC sensors in the detection of plasticizer contaminants.