DocumentCode :
844498
Title :
Microfabrication and characterization of teflon AF-coated liquid core waveguide channels in silicon
Author :
Datta, Arindom ; Eom, In-Yong ; Dhar, Achintya ; Kuban, Petr ; Manor, Rosalynn ; Ahmad, Iftikhar ; Gangopadhyay, Shubhra ; Dallas, Tim ; Holtz, Mark ; Temkin, Henryk ; Dasgupta, Purnendu K.
Author_Institution :
Nanotech Center, Texas Tech Univ., Lubbock, TX, USA
Volume :
3
Issue :
6
fYear :
2003
Firstpage :
788
Lastpage :
795
Abstract :
The fabrication and testing of Teflon AF-coated channels on silicon and bonding of the same to a similarly coated glass wafer are described. With water or aqueous solutions in such channels, the channels exhibit much better light conduction ability than similar uncoated channels. Although the loss is greater than extruded Teflon AF tubes, light throughput is far superior to channels described in the literature consisting of [110] planes in silicon with 45° sidewalls. Absorbance noise levels under actual flow conditions using an LED source, an inexpensive photodiode and a simple operational amplifier circuitry was 1× 10-4 absorbance units over a 10-mm path length (channel 0.17-mm deep ×0.49-mm wide), comparable to many commercially available macroscale flow-through absorbance detectors. Adherence to Beer´s law was tested over a 50-fold concentration range of an injected dye, with the linear r2 relating the concentration to the observed absorbance being 0.9993. Fluorescence detection was tested with fluorescein as the test solute, a high brightness blue LED as the excitation source and an inexpensive miniature PMT. The concentration detection limit was 3 × 10-9 M and the corresponding mass detection limit was estimated to be 5 × 10 -16 mol.
Keywords :
fluorescence spectroscopy; light emitting diodes; micro-optics; micromachining; optical waveguides; 0.17 mm; 0.49 mm; 10 mm; 50-fold concentration range; Beer law; LED source; absorbance noise levels; actual flow conditions; aqueous solutions; bonding; characterization; coated glass wafer; excitation source; fluorescein; fluorescence detection; high brightness blue LED; inexpensive photodiode; injected dye; light conduction; light throughput; liquid core waveguide channels; macroscale flow-through absorbance detectors; mass detection; microfabrication; miniature PMT; operational amplifier circuitry; path length; silicon; teflon AF; test solute; water solutions; Fabrication; Glass; Light emitting diodes; Liquid waveguides; Noise level; Photodiodes; Silicon; Testing; Throughput; Wafer bonding;
fLanguage :
English
Journal_Title :
Sensors Journal, IEEE
Publisher :
ieee
ISSN :
1530-437X
Type :
jour
DOI :
10.1109/JSEN.2003.820343
Filename :
1254556
Link To Document :
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