Foundation for Research and Technology-Hellas … of Electronic structure and Laser (IESL) ......
Transcript of Foundation for Research and Technology-Hellas … of Electronic structure and Laser (IESL) ......
National Technical University of Athens
School of Applied Mathematical and Physical sciences
Foundation for Research and Technology-Hellas (FORTH)
Institute of Electronic structure and Laser (IESL)
National Technical University of Athens
School of Applied Mathematical and Physical sciences
Terahertz detection
of harmful residues in honey
Dr. M. Massaouti
PHOTOTECH: BIOSENSORS & BIOCHIPS21st-25th October 2013 , Athens , Greece
National Technical University of Athens
THz radiation and Food industry
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Motivation
New methods for food analysis and inspection:
rapid portable (increase of testing capacity) non-destructive with no need of food pre-treatment real-time testing on the production line
Current analytical methods (few of them…)
High-performance liquid chromatography (HPLC)
Gas chromatography (GC)
mass spectrometry (MS)
nuclear magnetic resonance (NMR)
infrared spectroscopy (IR)
Fluorescence spectroscopy
Electrochemical (including also biosensors here), and so forth.
Contaminantsin food products
National Technical University of Athens
Terahertz radiation
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Molecular rotations ImagingLattice phononsSuperconductivity gap
Photonic “THz gap” Electronic
λ 10μm - 3mm
hν 120 - 0.413 meV
Hydrogen Bonds, Torsions, collective vibrational modes
National Technical University of Athens
Terahertz radiation
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Non–ionizing/invasive radiation
Transparent to non-conductingmaterials (paper, wood, plastic, etc.)
High sensitivity to water
Fingerprint spectrum:low-frequency torsional and vibrationalmotion of molecules
ImagingSecurity Drugs and explosives
Medical- Cancer
THz pump/probe
Plant stress
Ubiquitin: 76-residue, β-sheet protein
Protein folding DNA damage or repair
Discrimination of molecular structures
National Technical University of Athens
THz radiation and Food industry
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Detection of foreign bodies in food Non–ionizing/invasive radiation
Transparent to non-conductingmaterials (paper, wood, plastic, etc.)
High sensitivity to water
Fingerprint spectrum:low-frequency torsional and vibrationalmotion of molecules
Opt. Eng., 47 (3), 037003 (2007)
Moisture detectionJ Infrar. Milli. Terahz. Waves.33,97 (2012)
Grain wheat
Detection of Antibiotics/ pesticides (in milk, egg powders, rice, dried tomato)
Analyst, 136, 1733 (2012)IEEE Trans., 58, 7, 2064 (2010)
Appl. Spectr. Rev.,48, 439 (2013)
THz and Food industry
More to be done!!!
National Technical University of Athens
Food industry: Honey
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Honey: Natural and healthy product…….…..Polluted via different sources of contamination
(mainly to improper use of beekeeping practices)
Need: novel detection technologies rapid, non-destructive able todetermine the presence of multi-residues in honey.
Real-time detection
National Technical University of Athens
Terahertz source
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Broadband (0.1-35 THz), intense THz pulses (200 kV/cm)generated through 2-color femtosecond laser filaments in air.
THz source:
Coherent detection in time domain of the THz electric field.
National Technical University of Athens
Terahertz source
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Broadband (0.1-35 THz), intense THz pulses (200 kV/cm)generated through 2-color femtosecond laser filaments in air.
THz source:
Fourier transform the time signal
National Technical University of Athens
THz time-domain spectroscopy (THz-TDS)
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Refractive index
( )2ln
( )
S
R
Aa T
d A
Absorption coefficient:
( ) ( )1
s R cn
d
2( ( ) 1)
4 ( )
nT
n
( )( ) Ri
RA e
( )( ) si
SA e
National Technical University of Athens
THz spectra: Antibiotics & Acaricides
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Concentration 20% w/w
Thickness ~1 mm
Diameter 7 mm
Weight 40 mg
SAMPLE HOLDER(pellets)
PELLETS: mixture of HDPE powder + chemical compound
Antibiotics
Sulfapyridine
Sulfathiazole
Tetracycline
Acaricides Coumaphos
Amitraz
National Technical University of Athens
THz spectra : Antibiotics
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Sulfapyridine
Sulfapyridine
Sulfathiazole
Tetracycline
Tetracycline
THz region (0.5-2.6 THz)
1.064 THz
Sulfathiazole
1.88 THz2.04
Distinct resonance peaks in the THz regime
Massaouti et al. J. Appl. Spectr. (2013)
National Technical University of Athens
THz spectra : Acaricides
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Coumaphos
Amitraz
THz region (0.5-2.6 THz)
1.88 THz
Amitraz
Coumaphos
Distinct resonance peaks(0.5-2.6 THz)
↓Discrimination of:
Sulfapyridine
Sulfathiazole
Coumaphos
Massaouti et al. J. Appl. Spectr. (2013)
National Technical University of Athens
THz spectra : Antibiotics
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Sulfapyridine
Sulfathiazole
Tetracycline
THz region (0.5-6.0 THz)
Amitraz
Coumaphos
Detection in a wider THz region0.5-6.0 THz
↓Additional resonance peaks
↓Discrimination of:
Sulfapyridine
Sulfathiazole
Coumaphos
Amitraz
National Technical University of Athens
THz spectrum of honey
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SAMPLE HOLDER(liquids)
HDPE
Spacer 620 μm
Highly absorptive: α = 50 cm-1 (1 THz)
Refractive index: n = 1.8
Massaouti et al. J. Appl. Spectr. (2013)
National Technical University of Athens
Sulfapyridine in honey
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SAMPLE HOLDER(liquids)
HDPE
Spacer 620 μm
+
Mixture:
Sulfapyridine Honey
different concentrations(w/w)
1.064 THz
.
mixture honey sylfapyridine
mixture
THz ref
A
A
Massaouti et al. J. Appl. Spectr. (2013)
National Technical University of Athens
Sulfapyridine in honey
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SAMPLE HOLDER(liquids)
HDPE
Spacer 620 μm
+
Mixture:
Sulfapyridine Honey
different concentrations(w/w)
1.064 THz
Detection of Sulfapyridine in honey at relatively low concentrations (1% w/w)
National Technical University of Athens
Sulfapyridine & Sulfathiazole in honey
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+
Mixture:
Sulfapyridine (9%)
Honey
andSulfathiazole (11%)
binary mixture honey honey/ /
,
i ii
B
i sulfapyridine sulfathiazole
Multiple residues in honey
Potential of THz-TDS to be used in the near future as a fast, real-time technique for detecting and discriminating multi-residues strictly related
to food safety issues.
Massaouti et al. J. Appl. Spectr. (2013)
National Technical University of Athens
Ultrashort Nonlinear Interactions and Sources Lab
Acknowledgments
UNIS - THz group
Prof. S. Tzortzakis (Head of the UNIS group)
Dr. M. Massaouti
Dr. A. Gorodetsky
M. Loulakis
T. Koulouklidis
C. Daskalaki
http://www.iesl.forth.gr/
LASERLAB-EUROPE
UNIS group
http://unis.iesl.forth.gr/