Fluorescence based selfencoding microbead sensor arrays

1
Fluorescence based self-encoding micro-bead
sensor arrays
Analytical Chemistry Literature Seminar Louisiana
State University 12 October 2009 Joyce W. Kamande
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Overview

• Importance of Vapor Analysis
• Concept of Artificial nose
• Comparison with other techniques
• Objective
• Design and field implementation of a portable
  fluorescence based sensor
• Spectrally resolved sensor imaging
• Conclusion
• Critique
• Acknowledgements
• Questions

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Importance of Vapor Analysis

• Volatile organic compounds (VOC)
• Hazards Health liver, kidney, respiratory
• Environmental Pollution Ozone, BTX gases etc.
• Fragrances from flowers and perfumes
• Aromas from food and beverage
• Explosives volatile nitro aromatic compounds

http//www.texaninspection.com/graphics/pic_voc1.j
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Chemical Vapor Sensing Techniques

• Traditional Analytical Methods
• GC-Olfactometry
• GC-MS (mass spectroscopy)
• IMS ( ion mobilty spectroscopy)
• IR ( Infrared spectroscopy)
• Biological methods
• Canines (dogs)
• Human sensory panels
• Biomimetic methods
• Electronic noses

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dog/guarding_dog.jpg
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l_LG.jpg
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Biomimetics

• Biologically inspired technologies
• Highly fuel efficient car
• Electronic tongues which imitate the tongue and
  used for liquid sensing analysis which use
  potentiometric and voltametrics measure pH.
• Electronic noses imitate the human noses for
  gas sensing analysis

http//drvino.com/wp-content/uploads/2008/03/elect
ronictongue.jpg
http//specieslist.com/images/external/Mini4L.jpg
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Electronic Nose Concept
Orbitofrontal cortex
Thalamus
BIOLOGICAL NOSE
Olfactory bulb
Olfactory receptor cells
Olfactory epithelium
Nasal passage
Sensor elements Data acquisition system
ELECTRONIC NOSE
Pattern recognition algorithm
Vapor delivery system
http//www.electronichealing.co.uk/resources/Image
/olfactory_system.jpg
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About the Author

• Robinson Professor of Chemistry at Tufts
  University
• Founder and Director of Illumina Inc founded in
  1988 to commercialize bead arrays created in the
  Walt lab
• Published over 300 papers
• Well renown for pioneering work in optical bead
  arrays and has applied this concept to DNA and
  Protein Analysis
• .

Prof David R. Walt
http//www.vanderbilt.edu/vicb/Images/Walt.jpg
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Objective

• Discuss latest developments in fluorescence based
  micro bead sensor arrays for vapor detection.

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Nile Red Coating of Functionalized Silica
Microbeads
Non polar
Polar
SiO2
SiO2
SiO2
SiO2
C4
CN
NH2
OH
SiO2
SiO2
NH2
OH
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Solvatochromic effect of Nile Red
CN
OH
NH2
C4
Albert, K.and David R.Walt Anal. Chem.
2000,72,1947-1955
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Formation of Microwells in Optical Fibre bundles
Bundle of single core fibres
Etch in mixture of HF and NH4F
Microwells formed
watblog.com
Epstein,J,R.Walt,D.R.Chem.Soc.Rev.,2003,32,203-2
04
13
Micro-wells fabrication from optical fibers
Nile red coated functionalized silica Microbeads
(NRFSMB)
Optical fibre bundle with microwells
Optical fibre bundle packed with NRFSMB
Epstein,J,R.Walt,D.R.Chem.Soc.Rev.,2003,32,203-2
04
14
Instrumental Set Up
Pattern recognition system
Albert K,J et al., Environ. Sci. Technol.2001,35
3193-3200
Epstein,J,R.Walt,D.R.Chem.Soc.Rev.,2003,32,203-2
04
15
Imaging of the Fiber Optic Arrays
Sensor type a
Vapor pulse
Normalized intensity
Sensor type c
Sensor type b
Time (s)
Normalized intensity
Normalized intensity
Time (s)
Time (s)
Aernecke et al. Sensors and Actuators B Article
in press
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A
B
C
Mixture
Albert K,J et al., Environ. Sci. Technol.2001,35
3193-3200
Dickinson, T.A et al. Anal. Chem. 1999, 71,
2192-2198
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Design Implementation, and Field Testing of a
Portable Fluorescence- Based Vapor Sensor
Matthew J. Aernecke, Jian Guo, Sameer Sonkusale,
and David R. Walt Anal. Chem. 2009,81,5281-5290
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Portable Fluorescence-Based Vapor System
1
2
3
4
Mathew J. Aernecke, Jian Guo, Sameer Sonkusale,
and David R. Walt Anal. Chem. 2009,81,5281-5290
19
Fabrication Microbead Array

• Sensor type 1 ( Alltech)
• Sensor type 2 ( Chirex)
• Sensor type 3 (SCX)

Mathew J. Aernecke, Jian Guo, Sameer Sonkusale,
and David R. Walt Anal. Chem. 2009,81,5281-5290
20
Experimental Procedure
Air
Mathew J. Aernecke, Jian Guo, Sameer Sonkusale,
and David R. Walt Anal. Chem. 2009,81,5281-5290
21
Individual vs Block Segmentation
1
Intensity
0
Time
-1
1
Intensity
0
Run1
Run5
Time
-1
Run12
Run15
Mathew J. Aernecke, Jian Guo, Sameer Sonkusale,
and David R. Walt Anal. Chem. 2009,81,5281-5290
22
Experimental Procedure
Keith J.Albert and David R.Walt Anal. Chem.
2000,72,1947-1955
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Temporally Resolved Flourescence Spectroscopy of
a Microarray-Based Vapor Sensing System.
Mathew J. Aernecke. and David R. Walt Anal.
Chem. 2009, 81, 5762-5769
24
Spectrally Resolved Sensor Imaging (SRSI)
Transmission grating
First order
zero order
First order
Fluorescence intensity
Fluorescence intensity
Wavelength
time
time
Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
25
Spectrally Resolved Sensor Imaging(SRSI) Array
Fabrication
Dissolve the resist
Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
26
Instrumental Setup
Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
27
Instrumental Set Up
Mathew J. Aernecke- Correspondence with author
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Microbead Mapping on Array

• Luna C8
• Luna CN
• Luna OH

Bulk
Single sensor
Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
710
29
Time and Wavelength Resolved Response from a
Single Luna C8 Sensor to Ethanol
Ethanol
Air
Raw fluorescence intensity
Air
Raw fluorescence intensity
Time
wavelength
wavelength

• Exposure time 1 s
• Bathochromic shift of 23 nm

• Increase in intensity
• Response time 10 s

Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
30
Classification of Accuracies vs Wavelength
Classification Accuracy
Mathew J. Aernecke and David R. Walt Anal. Chem.
2009, 81, 5762-5769
31
Conclusions

• Signal to noise enhancement through the measured
  response of thousand of beads
• Portability-system captures all the essential
  elements of the larger laboratory based system.
• Increase in dimensionality using the SRSI
  improves the classification system from 61.9 to
  85.7
• SRSI is able to capture dynamic changes of a
  flourescence response from a single bead ( 10 s).
• System can be used to analyze petroleum
  distillates and Volatile Organic compounds

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Critiques

• The Luna C8 microbead sensor underwent
  photobleaching.
• Vapors with similar compositions could not
  clearly be distinguished by the pattern
  recognition system.
• Quantitative studies were not mentioned however
  given the saturated vapor pressures of the
  distillate the detection limits are estimated to
  lie between mid ppm to low ppm

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Acknowledgements

• Professor Soper
• Soper Research Group
• Audience