Preparation and application of EpCAM electrochemiluminescent aptamer sensor based on porous UiO-66(Ce) loading CdTe/CdS quantum dots

Abstract

Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein and its detection is important for diagnosis and therapeutic prognostic assessment of many cancers. Herein, a highly sensitive electrochemiluminescence (ECL) sensor was developed for its detection. In the ECL sensor, dimercaptosuccinic acid-capped core/shell structured CdTe/CdS quantum dot (QD) was loaded on metal-organic framework material UiO-66(Ce) as electrochemical luminophore; Ti₃C₂/Ag composite was introduced for immobilizing EpCAM aptamer. Due to the well immobilization of QD and catalysis of UiO-66(Ce), the obtained luminophore CdTe/CdS QDs@UiO-66(Ce) displayed a strong and stable ECL signal. Furthermore, the Ti₃C₂/Ag could act as a co-reactant accelerator to boost the ECL signal. Thus, the resulted sensor had quite strong initial ECL signal for signal-off detection. Further experiment showed that it exhibited good linear response to EpCAM over the concentration range of 1 pg mL⁻¹− 10 ng mL⁻¹ in pH 7.4 Tris buffer, with a detection limit low to 0.66 pg mL⁻¹. Additionally, the ECL sensor also presented high selectivity and satisfying reproducibility; its practicability was demonstrated by the successful determination of EpCAM in serum samples.