MoS2 quantum dots featured fluorescent biosensor for multiple detection of cancer

Abstract

Transition metal ions, such as those generated through MoS₂ material, possess an intrinsic fluorescence quenching property towards organic dye molecules; thus, they can be used to construct biosensors as quenchers. However, we found that the conventional bulk MoS₂ blocks the view of fluorescence imaging, and is incapable of tracing and visualizing mucin 1-overexpression cancer cells. Herein, a FAM fluorophore-labeled ssDNA fluorescent probe (P₀-FAM) stacked on the surface of MoS₂ quantum dots (QDs) was used to construct a MoS₂ QDs–P₀-FAM biosensor. MoS₂ QDs exhibit a high fluorescence quenching ability towards fluorescent dyes, possess large specific surface area and a large number of active sites to adsorb and quench more fluorescent probes, promoting sensitivity between quenching and the recovery signal. In addition, the lighter color of unstack-MoS₂ QDs is beneficial to define the location of cancer cells compared to MoS₂ nanosheets. The novel MoS₂ QDs-based biosensor demonstrates high sensitivity to MUC1 with a detection limit of 0.5 nM, and may become an important tool toward the detection of cancer cells.