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We present the dynamic study of optical trapping of fluorescent molecules using high-density gold nanodisk arrays. The gold nanodisks were fabricated by electron beam lithography with a diameter of 500 nm and a period of 1 μm. Dark-field illumination showed ~15 times enhancement of fluorescence near edges of nanodisks. Such enhanced near-field generated an optical trapping force of ~10 fN under 3.58 × 103 W/m2 illumination intensity as calculated from the Brownian motions of 590 nm polystyrene beads. Kinetic observation of thiolated DNA modified with Cy5 dye showed different binding rates of DNA under different illumination intensity. The binding rate increased from 2.14 × 103 s-1 (I = 0.7 × 103 W/m2 ) to 1.15 × 105 s-1 (I = 3.58 × 103 W/m2 ). Both enhanced fluorescence and binding rate indicate that gold nanodisks efficiently improve both detection limit and interaction time for microarrays. [ABSTRACT FROM AUTHOR]

Describes the design of soluble electroluminescent polyphenylene vinylene (PPV)-based copolymers bearing electron-deficient oxadiazole (OXD) moieties. Use of phenylene vinylene derivatives for device fabrication; Introduction of OXD through an alkylene spacer; Properties of OXD and PPV.