Bimetallic ZrHf-based metal-organic framework embedded with carbon dots: Ultra-sensitive platform for early diagnosis of HER2 and HER2-overexpressed living cancer cells

We report here a new bimetallic ZrHf metal–organic framework (ZrHf-MOF) embedded with abundant carbon dots (CDs) (denoted as [email protected]), which exhibits strong fluorescence and rich-amino-functionalization. The [email protected] can be applied as the scaffold for anchoring aptamer strands to determine human epidermal growth factor receptor-2 (HER2) and living HER2-overexpressed MCF-7 cells. The basic characterizations reveal that the CDs are embedded within the interior cavities of ZrHf-MOF without varying the nanostructure, leading to good biocompatibility, strong fluorescence, and high electrochemical activity of [email protected] As compared with the pristine ZrHf-MOF, the [email protected] electrochemical aptasensor displays better sensing performances toward both HER-2 and MCF-7 cells, giving an extremely low detection limit of 19 fg mL–1 (HER2 concentration range: 0.001–10 ng mL–1) and 23 cell mL–1 (cell concentration range: 1 × 102~1 × 105 cell mL–1), with good selectivity, stability, reproducibility, and acceptable applicability. The proposed strategy for developing [email protected] aptasensor is promising for the early and sensitive detection of cancer markers and living cancer cells.