Enhancement of fluorescence intensity from an immunoassay chip using high-aspect-ratio nanopillars fabricated by nanoimprinting

Abstract

High-aspect-ratio structures (nanopillars) were used to enhance the fluorescence intensity of immunoassay chips. Nanoimprinting with elongation phenomenon was applied to fabricate polystyrene nanopillars. Human alpha fetoprotein was detected by a fluorescence immunoassay protocol. Fluorescence intensities were evaluated for areas with nanopillars of different surface areas. The area with nanopillars of 95nm diameter and 4.1μm height showed fluorescence intensity 34 times higher than that of flat areas.

Size-controllable quartz nanostructure for signal enhancement of DNA chip

“…Although DNA chips have great potential as a high-throughput detection method, their sensitivity on planar substrates is not particularly high due to the limitation of mixing efficiency and probe immobilization capacity (Oillic et al, 2007a). Therefore, pillar-like nanostructures have been synthesized on solid substrate for the detection of biomolecules (Kuwabara et al, 2008;Murthy et al, 2008;Park et al, 2009). In this study, we controlled the height and spacing of pillar-like nanostructures and examined their impact on DNA detection sen- sitivity.…”

Enhanced Fluorescent DNA Microarray Using an Optical Interference Mirror Slide

“…Surface area enlargement by nanostructures leads to an increased density of immobilized DNA and antibody molecules and results in an improved sensitivity of target molecule detection. Seven-fold (8) and 34-fold (10) improvements of sensitivity were reported for the nanoporous and nanopillar substrates, respectively. An optical interference mirror (OIM) slide consisting of a multilayered structure with a metal film and a transparent dielectric thin film has been reported to provide a 100-fold enhancement of fluorescence from a fluorophore placed on the thin film.…”

“…A 10-fold improvement of the sensitivity of chip-based DNA detection has been reported with the silver nanoisland structure. (4) Moreover, fluorescence-enhancing substrates with nanoporous (6)(7)(8) and nanopillar (9)(10)(11) structures have been developed. These substrates can be fabricated on a Si substrate via anodization and photolithography.…”

Highly Sensitive Fluorescence Detection of Avidin/Streptavidin with an Optical Interference Mirror Slide

“…Such a structure can improve the sensitivity of target detection up to approximately 50-fold compared with that of a flat control surface. [9][10][11] In addition, porous and pillar structures with large surface areas can improve the sensitivity up to approximately 7-fold, [12][13][14] and 34-fold, [15][16][17] respectively. Among various substrates, we focused on an optical interference mirror (OIM) slide that consists of a plane mirror covered with an optical interference (OI) layer.…”