Article ID Journal Published Year Pages File Type
740305 Sensors and Actuators B: Chemical 2013 7 Pages PDF
Abstract

We theoretically and experimentally investigate the influence of the incident angle of illumination on the fluorescence enhancement for two kinds of gold nanohole arrays – a gold nanohole array on glass substrate (Au-hole array), and a gold coated photoresist nanohole array (Au/PR-hole array). Our simulations show that the absorption spectra for the Au/PR-hole array vary substantially with angle of incidence, whereas the corresponding spectra for the Au-hole array are marginally affected. The experimental results reveal fluorescence enhancement up to 14 and 12 times for the Au-hole array at an incident angle of 70° and the Au/PR-hole array at an incident angle of 20°, respectively. Moreover, a model sandwich immunoassay for the detection of prostate specific antigen (PSA) shows about 3-fold higher sensitivity on Au/PR-hole array as compared to planar gold at 70°. To the best of our knowledge this is the first investigation reporting on the relationship between the incident angle and the fluorescence enhancement on gold nanohole arrays. Our findings provide a solid foundation for designing a highly efficient fluorescence detection system with oblique angular illumination.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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