title: Synthesis of a red fluorescent dye-conjugated Ag@SiO2 nanocomposite for cell immunofluorescence.
abstract: In this work we describe a one-step approach for incorporating a red fluorophore (2SBPO) into core-shell nanoparticles for metal-enhanced fluorescence immunolabels. The 2SBPO-MEF nanoparticles are particularly attractive as cell labels because their ∼ 670 nm emission has minimal overlap with cell autofluorescence and from overlap with many conventional probes. 2SBPO was incorporated through physical entrapment during the Stöber process. Antibody-based cell labels were then synthesized using covalent linkage. The nanoparticle fluorescence was 7.5-fold higher than control nanoparticles lacking a metal core. We demonstrated labeling of CD4 + HuT 78 T lymphocytes using anti-CD4-conjugated nanoparticle labels. Cells labeled with anti-CD4 nanoparticles showed a 35-fold fluorescence signal compared to anti-CD4 coreless controls. This simple synthesis protocol can be applied to a variety of hydrophilic fluorophore types and has broad potential in bioanalytical and biosensing applications.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409 USA.
authors.forename: Meicong
authors.initials: M
authors.lastname: Dong
authors.forename: Yu
authors.initials: Y
authors.lastname: Tian
authors.forename: Dimitri
authors.initials: D
authors.lastname: Pappas
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry*; D005453:Fluorescence; D005455:Fluorescent Antibody Technique / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D053761:Nanocomposites / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010078:Oxazines / Q000737:chemistry*; D012822:Silicon Dioxide / Q000138:chemical synthesis*; D012834:Silver / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods
chemical_list: C000602455:9-di-3-sulfonylpropylaminobenzo(a)phenoxazonium; D055910:Antibodies, Immobilized; D005456:Fluorescent Dyes; D010078:Oxazines; D012834:Silver; D012822:Silicon Dioxide