title: Homogeneous detection of concanavalin A using pyrene-conjugated maltose assembled graphene based on fluorescence resonance energy transfer.
abstract: In this work, we proposed a novel biosensor to homogeneously detect concanavalin A (ConA) using pyrene-conjugated maltose assembled graphene based on fluorescence resonance energy transfer (FRET). Maltose-grafted-aminopyrene (Mal-Apy) was synthesized and characterized by mass spectra, UV-vis and fluorescence spectra. The Mal-Apy was further employed for fluorescence switch and ConA recognition. When Mal-Apy was self-assembled on the surface of graphene by means of π-stacking interaction, its fluorescence was adequately quenched because the graphene acted as a "nanoquencher" of the pyrene rings due to FRET. As a result, in the presence of ConA, competitive binding of ConA with glucose destroyed the π-stacking interaction between the pyrene and graphene, thereby causing the fluorescence recovery. This method was demonstrated the selective sensing of ConA, and the linear range is 2.0 × 10⁻² to 1.0 μM with the linear equation y=1.029x + 0.284 (R = 0.996). The limit of detection for ConA was low to 0.8 nM, and the detection of ConA could be performed in 5 min, indicating that this method could be used for fast, sensitive, and selective sensing of ConA. Such data suggests that the graphene FRET platform is a great potential application for protein-carbohydrate studies, and would be widely applied in drug screening, bimolecular recognition and disease diagnosis.
authors.affiliation: Analysis Center and Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
authors.forename: Qiushui
authors.initials: Q
authors.lastname: Chen
authors.forename: Weili
authors.initials: W
authors.lastname: Wei
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D003208:Concanavalin A / Q000032:analysis*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods* / Q000706:statistics & numerical data; D006108:Graphite; D057230:Limit of Detection; D008320:Maltose; D018625:Microscopy, Atomic Force; D011721:Pyrenes
chemical_list: D011721:Pyrenes; D003208:Concanavalin A; D008320:Maltose; D006108:Graphite