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Nanoscale Plasmonic Interferometers for Multispectral, High-Throughput Biochemical Sensing

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journal contribution
posted on 08.02.2012, 00:00 by Jing Feng, Vince S. Siu, Alec Roelke, Vihang Mehta, Steve Y. Rhieu, G. Tayhas R. Palmore, Domenico Pacifici
In this work, we report the design, fabrication, and characterization of novel biochemical sensors consisting of nanoscale grooves and slits milled in a metal film to form two-arm, three-beam, planar plasmonic interferometers. By integrating thousands of plasmonic interferometers per square millimeter with a microfluidic system, we demonstrate a sensor able to detect physiological concentrations of glucose in water over a broad wavelength range (400–800 nm). A wavelength sensitivity between 370 and 630 nm/RIU (RIU, refractive index units), a relative intensity change between ∼103 and 106 %/RIU, and a resolution of ∼3 × 10–7 in refractive index change were experimentally measured using typical sensing volumes as low as 20 fL. These results show that multispectral plasmonic interferometry is a promising approach for the development of high-throughput, real-time, and extremely compact biochemical sensors.