Fabrication of “Clickable” Polyfluorene Nanowires with High Aspect Ratio as Biological Sensing Platforms

“Clickable” nanowires with well-defined and uniform structures made of conjugated polyfluorene polymers were successfully fabricated by single particle nanofabrication technique (SPNT). Poly[(9,9-dihex-5-yn-1-ylfluorenyl-2,7-diyl)-co-(9,9′-di-n-octylfluorenyl-2,7-diyl)] (F6E8) and poly[(9,9-dihex-5-yn-1-ylfluorenyl-2,7-diyl)-co-(2,2′-bithiophene)] (F6E2T) underwent an efficient cross-linking reaction upon irradiation, resulting in formation of one-dimensional nanostructures with high and desired aspect ratio reaching up to 200. Alkyne groups on the surface of nanowires were functionalized effectively by click reaction with fluorescent 5-TAMRA-PEG3-azide, which was confirmed by confocal microscopy. Substrates functionalized with the nanowires provide dramatic expansion of “clickable” surface area immobilized directly with TAMRA, and the fluorescence resonance energy transfer (FRET) processes between TAMRA and nanowire backbones are demonstrated as biological sensing platforms.