Details

Autor(en) / Beteiligte

• Jones, Robert M.
• Lu, Liangde
• Helgeson, Roger
• Bergstedt, Troy S.
• McBranch, Duncan W.
• Whitten, David G.

Titel

Building Highly Sensitive Dye Assemblies for Biosensing from Molecular Building Blocks

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2001-12, Vol.98 (26), p.14769-14772

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2001

Quelle

MEDLINE

Beschreibungen/Notizen

• Fluorescence superquenching is investigated for polyelectrolytes consisting of cyanine dye pendant polylysines ranging in number of polymer repeat units (NPRU) from 1 to 900, both in solution and after adsorption onto silica nanoparticles. As NPRUincreases, the absorption and fluorescence evolve from monomer spectra to red-shifted features indicative of molecular J aggregates. In solution, the superquenching sensitivity toward an anionic electron acceptor increases by more than a millionfold over the NPRUrange from 1 to 900. The dramatic increase is attributed to enhanced equilibrium constants for binding the quenchers, and the amplified quenching of a delocalized exciton of ≈100 polymer repeat units. The self-assembly of monomer onto silica and clay nanoparticles leads to formation of J aggregates, and surface-activated superquenching enhanced 10,000× over the monomer in solution, indicating the formation of "self-assembled polymers" on the nanoparticle surface. Utilization of these self-assembled polymers as high-sensitivity biosensors is demonstrated.