A fluorescence turn-on biosensor based on graphene quantum dots (GQDs) and molybdenum disulfide (MoS2) nanosheets for epithelial cell adhesion molecule (EpCAM) detection.
This paper presents a "turn-on" fluorescence biosensor based on graphene quantum dots (GQDs) and molybdenum disulfide (MoS2) nanosheets for rapid and sensitive detection of epithelial cell adhesion molecule (EpCAM). PEGylated GQDs were used as donor molecules, which could not only largely increase emission intensity but also prevent non-specific adsorption of PEGylated GQD on MoS2 surface. The sensing platform was realized by adsorption of PEGylated GQD labelled EpCAM aptamer onto MoS2 surface via van der Waals force. The fluorescence signal of GQD was then quenched by MoS2 nanosheets via fluorescence resonance energy transfer (FRET) mechanism. In the presence of EpCAM protein, the stronger specific affinity interaction between aptamer and EpCAM protein could detach GQD labelled EpCAM aptamer from MoS2 nanosheets, leading to the restoration of fluorescence intensity. By monitoring the change of fluorescence signal, the target EpCAM protein could be detected sensitively and selectively with a linear detection range from 3nM to 54nM and limit of detection (LOD) around 450pM. In addition, this nanobiosensor has been successfully used for EpCAM-expressed breast cancer MCF-7 cell detection.
['Shi|Jingyu|J|', 'Lyu|Jing|J|', 'Tian|Feng|F|', 'Yang|Mo|M|']
D052157:Aptamers, Nucleotide D015374:Biosensing Techniques D004220:Disulfides D000071858:Epithelial Cell Adhesion Molecule D005453:Fluorescence D006108:Graphite D006801:Humans D061986:MCF-7 Cells D008982:Molybdenum D045663:Quantum Dots
Graphene quantum dots (GQDs) Epithelial cell adhesion molecule (EpCAM) Fluorescence resonance energy transfer (FRET) Molybdenum disulfide (MoS(2))