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Title: Enhancing DNA binding rate using optical trapping of high-density gold nanodisks

Journal Article · · AIP Advances
DOI:https://doi.org/10.1063/1.4869640· OSTI ID:22250682
;  [1];  [1];  [2]
  1. Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan 30013 (China)
  2. Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 11529 (China)

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 × 10{sup 3} W/m{sup 2} 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 × 10{sup 3} s{sup −1} (I = 0.7 × 10{sup 3} W/m{sup 2}) to 1.15 × 10{sup 5} s{sup −1} (I = 3.58 × 10{sup 3} W/m{sup 2}). Both enhanced fluorescence and binding rate indicate that gold nanodisks efficiently improve both detection limit and interaction time for microarrays.

OSTI ID:
22250682
Journal Information:
AIP Advances, Vol. 4, Issue 3; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
Country of Publication:
United States
Language:
English