title: Fluorescence imaging for in situ detection of cell surface sialic acid by competitive binding of 3-(dansylamino)phenylboronic acid.
abstract: Sialic acid (SA) usually locates at the terminal position of the sugar chains on cell membranes, and its expression level is closely associated with cancer. Here polysialic acid (PSA) embedded gold nanoparticles (AuNPs) were prepared and functionalized with fluorescent 3-(dansylamino)phenylboronic acid (DAPB) for in situ imaging and detection of cell surface SA. The fluorescence resonance energy transfer (FRET) from DAPB to AuNPs quenched the fluorescence of DAPB. In the presence of additional SA or SA-abundant cells, the competitive binding of DAPB with SA and PSA led to the release of the assembled DAPB from the surface of PSA-embedded AuNPs, resulting in fluorescence of DAPB on SA-abundant cell surface. The proposed methods realized the in situ imaging and monitoring of cell surface SA, and could also be applied to the quantification of cell number and the amounts of cell surface SA. This work not only proposed a convenient visualization method for the analysis of SA on cell membranes, but also provided a potential tool for accelerating the elucidation of the basic role of SA in various biological processes and development of anti-cancer therapies.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China.
authors.forename: Ruocan
authors.initials: R
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, PR China. Electronic address: hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D000588:Amines / Q000737:chemistry*; D001667:Binding, Competitive; D001897:Boronic Acids / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D003619:Dansyl Compounds / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D019158:N-Acetylneuraminic Acid / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D000588:Amines; D001897:Boronic Acids; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D019158:N-Acetylneuraminic Acid; C010686:benzeneboronic acid
keywords: 3-(Dansylamino)phenylboronic acid; Cell imaging; Fluorescence resonance energy transfer; Gold nanoparticles; In situ monitoring; Sialic acid