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 MoS2surface. The sensing platform was realized by adsorption of PEGylated GQD labelled EpCAM aptamer onto MoS2surface via van der Waals force. The fluorescence signal of GQD was then quenched by MoS2nanosheets 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 MoS2nanosheets, 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.
Interdisciplinary Division of Biomedical Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Jingyu
J
Shi
Interdisciplinary Division of Biomedical Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Jing
J
Lyu
Interdisciplinary Division of Biomedical Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Feng
F
Tian
Interdisciplinary Division of Biomedical Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China. Electronic address: Mo.Yang@polyu.edu.hk.
Mo
M
Yang
D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D004220:Disulfides / Q000737:chemistry; D000071858:Epithelial Cell Adhesion Molecule / Q000096:biosynthesis / Q000302:isolation & purification*; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D061986:MCF-7 Cells; D008982:Molybdenum / Q000737:chemistry; D045663:Quantum Dots
D052157:Aptamers, Nucleotide; D004220:Disulfides; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D006108:Graphite; D008982:Molybdenum; C082964:molybdenum disulfide
Epithelial cell adhesion molecule (EpCAM); Fluorescence resonance energy transfer (FRET); Graphene quantum dots (GQDs); Molybdenum disulfide (MoS(2))