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A New Potentiometric Method for Automated Detection of Bioaerosols
Dimitris Sarantaridis and D.J. Caruana
Department of ChemistryUniversity College London
UK
Current & Future Air Quality MonitoringLondon, 15 Dec 2010
Case for bioaerosol detection ‐ Current technologies
Flame Plasma Electrochemistry Concept
Setup
Potentiometry/Imaging Results of Pollen
Analysis/Discussion
Pros/Cons ‐ Conclusions
Outline
A case for general bioaerosol detection
o Viruses o Bacterial sporeso Fungal sporeso Pollen
R. Joseph and R. Schild, J. Cosmology, 7, 1616 (2010).http://journalofcosmology.com/Panspermia1.html
A case for pollen
http://jeromeprophet.blogspot.com/2007/07/illinois‐worlds‐mold‐and‐pollen‐capital.html
General bioagents detection: state‐of‐the‐art
ELISA (enzyme immunoassay)
PCR (polymerase chain reaction)
http://www.interferonsource.com/New_InterferonSource/ELISA/ELISA_Description.html
https://www.llnl.gov/news/newsreleases/2008/NR‐08‐06‐05.html
Single‐Particle Aerosol Mass spectrometry
Lawrence Livermore National Laboratory
Emerging technologies
P.T. Steele et al., Anal. Chem., 80 4583 (2008).
http://www.pollenuk.co.uk/aero/pm/RPC1.htm
Burkard sampler (UK)
Pollen detection: state‐of‐the‐art
Emerging technologies
http://www.shinyei.co.jp/stc/optical/poln/poln_e.html
Shinyei (Japan)
J.J. Delaunay et al., Ann. Allergy Asthma Immunol., 98 553 (2007).
Flame plasma electrochemistry concept
H2 flame
Rationale
Grain/spore injection
Breakdown‐amplification
Ionisation‐charge separation
Voltage detection
electrodes
Hypothesis
Voltage generated uniquely related to size and physical properties of
combusted particle
D. J. Caruana and J. Yao, The Analyst, 128, 1286 (2003).
H2
O2
N2
MFCmixingchamber
MFC
MFC
40.00 mm
Setup
syringe pump
sample chamber
voltage dataacquisition 100 kHz
burner
5 k fps
50 μm
Results
Samples
Black walnut pollen
Bermuda grass pollen
25 μm
37 μm
0.0 0.5 1.0 1.5 2.0 2.5-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
time / s
volta
ge /
Vbaseline
pollen signal
The big picture
Bermuda pollen burning
5 mm
single event
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
1
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
2
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
3
single event
5 mm
4
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
5
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
6
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
7
Potentiometry
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 1.8
volta
ge /
V
time / ms
single event
5 mm
0
0.2
0.4
0.6
0.8Flame3
-0.2
0
0.2
0.4
0.6
0 20 40 60 80 100
time / ms
Flame6
0.5 1 1.5 2 2.5 3
time / ms
-0.4
-0.2
0
0.2
0.4
volta
ge /
V
Flame3
-0.2
0
0.2
0.4
0.6
0 20 40 60 80 100
volta
ge /
V
time / ms
Flame6
0.5 1 1.5 2 2.5 3
time / ms
Pollens comparison
Bermuda Walnut
1100 °C
1200 °C
1100 °C
1200 °C
D. Sarantaridis and D.J. Caruana, Anal. Chem., 82, 7660 (2010).
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0 0.5 1 1.5 2 2.5 3
volta
ge /
V
time / ms
Bermuda single slope
Walnut dual slope
Pollens comparison
Concept Pros/Cons
Method can detect/count single pollen combustion events
Promising results for discriminating between different species
Great potential for a low cost versatile automatic sensor system
Conclusions
Test other bio and non‐bio aerosols
Build prototype
Next steps
Engineering and Physical Sciences Research Council Contract no. EP/F028423/1
Engineering Instrument Loan Pool
Beloe Fellowship
The Worshipful Company of Scientific Instrument Makers
Richard Gilham
Acknowledgments
Thank You