Bimetallic organic framework Cu/UiO-66 mediated “fluorescence turn-on” method for ultrasensitive and rapid detection of carcinoembryonic antigen (CEA)

Carcinoembryonic antigen (CEA) is a key serum tumor marker which is overexpressed in all types of adenocarcinomas. Therefore, establish the ultrasensitive, accurate and rapid method for CEA detection is essential for reducing the mortality of cancer. Here, a bimetallic organic framework Cu/UiO-66 was synthesized through the simple two-step hydrothermal method and used to construct a “fluorescence turn-on” analytical method for CEA detection. Cu/UiO-66 can adsorb CEA aptamers modified with FAM (CEA/FAM-Apt) and take place photoinduced electron transfer (PET) between Cu/UiO-66 and FAM, resulting in the fluorescence of the FAM is quenched. When CEA is present, CEA and CEA/FAM-Apt are tightly combined, making CEA/FAM-Apt far away from the Cu/UiO-66 surface. As a result, the fluorescence intensity of the system was significantly restored. Under optimal conditions, the proposed “fluorescence turn-on” method can detect CEA as low as 0.01 ng mL−1 in a range of 0.01–0.3 ng mL−1. Besides, this analytical method owns good selectivity, reproducibility and serum applicability, which provides a new platform for the direct detection of clinical diagnosis-related markers.