Photo acoustic spectroscopy of beta amyloids - research overview

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Photo acoustic spectroscopy of beta amyloids - research overview Group Meeting February 08

description

Photo acoustic spectroscopy of beta amyloids - research overview. Group Meeting February 08. First setup. goal –generating and characterization of pa signal Wavelength – 1550 nm. 1 . OTDR. OTDR pulse width: 100ns-1 μ s. PZT. fiber splitter. Erbium Amplifier. 90%. 10%. - PowerPoint PPT Presentation

Transcript of Photo acoustic spectroscopy of beta amyloids - research overview

Page 1: Photo acoustic spectroscopy of beta amyloids - research overview

Photo acoustic spectroscopy of beta amyloids - research overview

Group Meeting February 08

Page 2: Photo acoustic spectroscopy of beta amyloids - research overview
Page 3: Photo acoustic spectroscopy of beta amyloids - research overview

OTDRpulse width: 100ns-1μs

Scope

detector

10%

fibersplitter

Erbium Amplifier

90%

PZT

RF Amplifier

24V+ Voltage source

reference Photo-acoustic signal

First setup goal –generating and characterization of pa signal

Wavelength – 1550 nm

1. OTDR

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Page 5: Photo acoustic spectroscopy of beta amyloids - research overview

TunableLaser

Polarization controller

Modulator Function Generator

Erbium Amplifier x2

Scope

PZT

RF Amplifier x3

24V+ Voltage sourcedetector

fibersplitter

Reference

95%

Signal

5%

2. Tunable Laser

Wavelength 1535 -1565 nm

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Page 7: Photo acoustic spectroscopy of beta amyloids - research overview

~5 micro second

~5 micro second

PZT

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abs coefficient

-10

10

30

50

70

90

110

130

1000 1200 1400 1600 1800 2000

nm

cm

^-1

ddw

ethanol

3.85ethanol

water

P

P

Water:

Abs coefficient =11.6 cm^-1

heat capacity = 4.184J cm-3 K-1   

Thermal expansion =20710-6/K

ethanol:Abs coefficient =5.7 cm^-1

heat capacity = 1.925J cm-3 K-1   Thermal expansion =75010-6/K

0PP

E

C

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second peak amp of glucose in diff conentrations

0

20

40

60

80

100

0 20 40 60

glucose concentration in water(%)

amp

of

pea

k

Series1

•There is a change of 0.28% in sound velocity for a percent change of glucose concentration

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200 800 2,000300 10,000

UV visible Near-IR IR

nm

1550

peptidic bond(190-250 nm)

aromatic residues(~280nm) starching vibration of aromatic residues(3.3, 6.25,6.6 μm )

starching vibration of amide bond (5.88-6.25 μm )

bending vibration of aromatic residues (11.1-14.5 μm)

Over tones (1000-2600)

Spectrum

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0

0.5

1

1.5

2

2.5

3

3.5

180 200 220 240 260 280 300

insulin 200

insulin 400

Technion experiment :

Nd:YAG fourth harmonic 266nm laser:

1.Insulin

0 500 1000 1500 2000 2500-4

-3

-2

-1

0

1

2

3

4

5Insulin (-offset)

Insulin 200M

Insulin 400M

Insulin 100M

Insulin 50MBuffer Gly (with small ins c.)Native(400 M) Insulin in H2O

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0 500 1000 1500 2000 2500-8

-6

-4

-2

0

2

4

6Lyso 50mg 1stH2OLyso 50mg 2ndLyso 25mgLyso 12.5mgLyso 6.25mgH2O(small protein concentration)H2O 2nd

2.lysosin

3.Beta amyloid

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opo experiment:OPO -optical parametric oscillator

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0

0.5

1

1.5

2

2.5

3

3.5

1000 1200 1400 1600 1800 2000

D2O 0.5

lysozyme D2O 0.5

insulin native D2O 0.5

insulin amyloid D2O 0.5

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

1600 1650 1700 1750 1800

D2O 0.5

lysozyme D2O 0.5

insulin native D2O 0.5

insulin amyloid D2O 0.5

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Zoom in on first peak

1100 1200 1300 1400 1500 1600 1700 18000

5

10

15

20

25

30

35Water absorption & 1st peak of acoustic signals (multiplied by 50)

wavelength (nm)

water absorptionabsorption in gratings wavelength

1 .insulin

2 .water

Wavelength ~1660nm

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Goals for the short future

improving the sensitivity of the measurements

Defining the concentration and absorption coefficient of solutions by pa measurement

Finding the amyloids over tones spectra , and characterize its pa signal

Examine the ability of performing pa measurements in the MIR

Completing the simulation of the pa signal