Sensitive biosensor array using surface plasmon resonance on metallic nanoslits

Abstract

Chip-based biosensor arrays for label-free and high-throughput detection were fabricated and tested. The sensor array was composed of a 150-nm-thick, 50-nm-gap, and 600-nm-period gold nanoslits. Each array size was 100 mumx100 mum. A transverse-magnetic polarized wave in these metallic nanostructures generated resonant surface plasmons at a wavelength of about 800 nm in a water environment. Using the resonant wavelength shift in the nanoslit array, we achieved detection sensitivity up to 668 nm per refractive index unit, about 1.7 times larger than that reported on an array of nanoholes. An antigen-antibody interaction experiment in an aqueous environment verified the sensitivity in a surface binding event.

Comparisons of Surface Plasmon Sensitivities in Periodic Gold Nanostructures

“…Tens of thousands of SPR detection points can be put on a glass slide. Therefore, periodic metallic nanostructures are very suitable for high-throughput and chip-based detections [8][9][10].…”

Improving Surface Plasmon Detection in Gold Nanostructures Using a Multi‐Polarization Spectral Integration Method

“…[4][5][6][7] Recently, periodic gold nanohole arrays or nanoslit arrays have been utilized for biosensing applications. [8][9][10][11][12][13][14][15][16][17][18][19] By measuring changes in the resonant angle, wavelength or intensity, the amounts of surface binding events are quantitatively estimated. The detection limit of the SPR sensor is usually characterized by minimum refractive index unit (RIU).…”

Modeling and optimization of Au-GaAs plasmonic nanoslit array structures for enhanced near-infrared photodetector applications

“…[5][6][7][8][9][10][11][12][13] Applications of devices containing nanoslit structures include biosensors, 5,14 terahertz antennas, 9 and lenses with controllable parameters. [15][16][17][18] Experimental and theoretical research has confirmed that not only can these nanostructures enhance an incident electric field, but also the nanogaps that separate them can provide additional enhancement.…”