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Multicolor Fluorescence Detection for Droplet Microfluidics Using Optical Fibers
Published on: May 5, 2016
Optical fiber coupled light emitting diode based absorbance detector with a reflective flow cell.
S Jambunathan1, P K Dasgupta, D K Wolcott
1Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
Talanta
|October 31, 2008
Summary
This study introduces a flexible optical fiber-coupled absorbance detector using a changeable light-emitting diode (LED) source. It offers low noise and linear response for sensitive chemical analysis in flow systems.
Area of Science:
- Analytical Chemistry
- Spectroscopy
- Optical Instrumentation
Background:
- Traditional flow-through detectors can be susceptible to electrical noise and refractive index variations.
- Integrating light sources and detectors directly in flow cells limits remote operation and flexibility.
Purpose of the Study:
- To develop a versatile, fiber-coupled absorbance detector with a remotely located, interchangeable light-emitting diode (LED) source.
- To minimize electrical noise and refractive index sensitivity in flow-based optical detection.
Main Methods:
- Utilized optical fibers to transmit light from a changeable LED source to a reflective flow-through cell and back.
- Designed a linear flow path with a large aperture to prevent bubble trapping.
- Employed an orthogonal light path and rear mirror reflection to reduce refractive index sensitivity.
Main Results:
- Achieved low noise levels (3-20 muAU) and minimal drift (4 muAU/min) under operational conditions.
- Demonstrated linear detector response with concentration over at least two orders of magnitude when absorbance is matched to the LED emission.
- Reduced refractive index sensitivity by an order of magnitude compared to conventional Z-path flow cells.
Conclusions:
- The developed fiber-coupled LED absorbance detector is a versatile and robust tool for sensitive chemical analysis.
- Its design allows for remote cell placement, immunity to electrical noise, and reduced sensitivity to refractive index changes.
- This detector offers a linear response and low noise, making it suitable for various flow-based analytical applications.
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