photo acoustic spectroscopy of beta amyloids - research overview
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 PresentationTRANSCRIPT
Photo acoustic spectroscopy of beta amyloids - research overview
Group Meeting February 08
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
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
~5 micro second
~5 micro second
PZT
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
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
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
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
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
opo experiment:OPO -optical parametric oscillator
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
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
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