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Journal of Biomedical Optics • Open Access

Microfluidic surface-enhanced Raman scattering sensor with monolithically integrated nanoporous gold disk arrays for rapid and label-free biomolecular detection
Author(s): Ming Li; Fusheng Zhao; Jianbo Zeng; Ji Qi; Jing Lu; Wei-Chuan Shih

Paper Abstract

We present a microfluidic surface-enhanced Raman scattering (SERS) sensor for rapid and label-free biomolecular detection. Our sensor design mitigates a common limiting factor in microfluidic SERS sensors that utilize integrated nanostructures: low-efficiency transport of biomolecules to nanostructured surface which adversely impacts sensitivity. Our strategy is to increase the total usable nanostructured surface area, which provides more adsorption sites for biomolecules. Specifically, a nanoporous gold disk (NPGD) array, a highly effective SERS substrate, has been monolithically integrated inside a microfluidic chip. Individual NPGD is known to feature an order of magnitude larger surface area than its projected disk area. The increased surface area arises from nanoscale pores and ligaments three-dimensionally distributed in the NPGD, which manifest themselves as high-density SERS hot-spots. High-density NPGD arrays further guarantee large coverage of these hot-spots on the microchannel floor. The sensor performance has been demonstrated using Rhodamine 6G to quantify spatial uniformity and determine the shortest detection time. Next, the sensor is applied to detect two biomolecules, dopamine and urea, with unprecedented detection limit and speed compared to other existing microfluidic SERS sensors. The sensor holds great promise in point-of-care applications for various biomolecular detections.

Paper Details

Date Published: 23 July 2014
PDF: 8 pages
J. Biomed. Opt. 19(11) 111611 doi: 10.1117/1.JBO.19.11.111611
Published in: Journal of Biomedical Optics Volume 19, Issue 11
Show Author Affiliations
Ming Li, Univ. of Houston (United States)
Fusheng Zhao, Univ. of Houston (United States)
Jianbo Zeng, Univ. of Houston (United States)
Ji Qi, Univ. of Houston (United States)
Jing Lu, Univ. of Houston (United States)
Wei-Chuan Shih, Univ. of Houston (United States)

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