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OPTIČNI KEMIJSKI SENZORJI IN
NJIHOVE APLIKACIJE
Aleksandra Lobnik
UNIVERZA V MARIBORU,
Fakulteta za strojništvo,
Center za senzorsko tehniko
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Vsebina
1. Optični kemijski senzorji
2. Indikatorska kemija
3. Molekularni imprinting
4. Vlaknasti optični senzorji
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Shema sestave in funkcije
kemijskega senzorja
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1. Optični kemijski senzor
“Optrode” - (fiz optične elektrode) and “optode” (iz grške besede –
optična pot)
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za detekcijo uporabimo optično lastnost samega analita
Uporabimo indikatorje kadar analit sam nima optične lastnosti
Vlaknasti optični kemijski senzorji (FOCSs) predstavljajo podrazred
kemijskih senzorjev, kjer se optično vlakno uporablja kot del
pretvornika (transducerja).
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2. Indikatorska kemija
Indikatorji
Polimeri
Imobilizacijske tehnike
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Lantanidni kelati
relative intensity
10
ligand (ex/em = 315/405 nm)
3+
complex with Tb (ex/em = 315/547 nm)
• ozki emisijski piki
• veliki Stokovi shifts (≥ 200 nm)
8
6
4
2
0
300
400
500
wavelength (nm)
600
• dolge življenske dobe
vzbujenega stanja (od mikro- do
nekaj mili-sekund)
→ lifetime-based assays advantageous
over intensity-based: higly immune to
photobleaching, changes in
fluorophore concentration, tubidity in
the sample, optical misalignment, etc.
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Sol-gel materiali
1. hydrolysis
Si(OR)4 + H2O
HO-Si(OR)3 + ROH
2. condensation:
HO-Si(OR)3 + HO-Si(OR)3
HO-Si(OR)2-O-Si(OR)2 + HOH
HO-Si(OR)3 + Si(OR)4
Si(OR)3-O-Si(OR)3 + ROH
Monomers
Other Metals
Si(OR’)4
Zr(OR’)4
R1-Si(OR’)3
R1-Zr(OR’)3
R1 R2 -Si(OR’)2
R1 R2 -Zr(OR’)2
R: aliphatic, aromatic
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Ti, Sn
APLIKACIJE
Optični kemijski senzorji za
določevanje plinov, pH in ionov
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Medicina
Okolje
Procesni parametri
Kontrola hrane
Osebna zaščita
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APLIKACIJE
Optični kemijski senzorji za
določevanje plinov, pH in ionov
CO2
Na+
K+
O2
tHb/SO2
pH
Ca++
or Cl-
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SENSORSKA TEHNOLOGIJA
O2 Optoda
Indicator
layer
O2
120
rel. flu. intensity S
Black
overcoat
100
80
60
40
20
0
Dye
0
100
200
P O2 [ Torr ]
blue light
red light
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300
SENZORSKA TEHNOLOGIJA
Na+, K+ and Ca++ Optode
Potassium-FI
Sodium-FI
O
O
O
N
O
O
N
O
N
ionophore
O
O
Calcium-FI
COO
-
O
O
O
N
O
O
N
O
COO
O
O
O
e-
H
e-
spacer
N
H
O
N
H
N
O
N
N
O
hν1
-
O
fluorophore
N
hν 1
e
O
O
linker
hydrophilic
polymer
hydrophilic polymer
O
hydrophilicpolymer
polymer
hydrophilic
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O
hydrophilic
hydrophilicpolymer
polymer
O
-
pH optični kemijski senzor
fluorescence intensity
125
pH=6
pH=7.00
100
pH=7.88
pH=8.32
75
50
pH=9.98
25
0
400
500
wavelength /nm
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600
700
Amonijev senzor
120
20 ppm
10 ppm
90
fluorescence intensity
fluorescence intensity
100
5 ppm
80
1 ppm
buffer
70
60
50
80
pH=7.4 pH=5.0 pH=8.3 pH=4.7 pH=6.5 pH=5.0
40
0
0
300
600
900
1200
1500
1800
time /s
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0
100
200
300
time / s
400
500
Detekcija aluminija
Indicator Morin
Al-Morin complex
Al
OH
O
O
OH
OH
HO
+
O
O
OH
OH
Al3+
HO
O
OH
non-fluorescent
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OH
yellow-green
fluorescent
(at pH 3.5)
Determination of phosphate (P)
using terbium-ligand complex (TbL)
TbL
TbL
+ PO43-
Ex = 320 nm
Em = 548 nm
10 mM HEPES, pH 7.4
Tb:L = 1:1,
[TbL] = 1 µM
Incubation time = 20 min
T = 25 °C
intenziteta luminescence (a.u.)
Response of TbL to P
10
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0 µM P
8
6
4
2
0
480
500 µM P
500
520
540
560
580
valovna dolžina (nm)
600
3. Molecularni Imprinting
Non-covalent Approach
Self-assembly
Polymerisation
Solvent extraction
Rebinding
Covalent Approach
Synthesis of
polymerisable
template
Polymerisation
Extraction
by chemical
cleavage
Rebinding
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MOLECULARLY IMPRINTED POLYMERS
2,4 - D
Nitrophenol
Cl
O
H3C
OH
O
COOH
OH
O
2,4-Dichlorophenoxyacetic acid (2,4-D)
OH
4-Nitrophenol
NO2
OH
OH
Deoxynivalenol (DON)
OH
O
O
HO
CH
OH 3
§ Application in Solid
Phase Extraction (SPE)
O
OH
O
Cl
Future
Perspectives
Flavones
Mycotoxins
OH
Quercetin
CH3
OH
OMe
O
O
HO
HO
OCH2CH3
O
O
O
§ Characterization by
HPLC and radioligand binding assay
§ Works in organic
and aqueous media
§ Application in IREWS
§ Characterization by
HPLC and radioligand binding
assay
§ Works in organic
and aqueous
media
Zearalenone (ZON)
§ High demand
§ Characterization by
HPLC of DON and
ZON
§ Template expensive
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2-Carbethoxy-5,7-dihydroxy4'-methoxyisoflavone
§ Characterization by
HPLC of flavonoids
§ Application in SPE
§ Real-world samples
(red wine)
§ Formation of planar
MIP recognition layers
for IR-EWS
§ Application in Solid
Phase Micro Extraction
§ Enhancement in
terms of selectivity and
binding capacity
§ Generation of MIPs
applicable in organic
and aqueous media
§ Combination SPRMIP
§ Sol-Gel Imprints
Vlaknasti optični kemijski senzorji
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Aplikacija OKS na optična vlakna
Svetloba iz svetlobnega izvora
Emitirana svetloba
Optično vlakno
Svetloba iz svetlobnega
izvora
Senzorska membrana
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Senzorska membrana
Emitirana svetloba
Optično vlakno
Zahvaljujem se svojim sodelavcem
Centra za senzorsko tehniko
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Doc. dr. Andreja Gutmaher
Dr. Matejka Turel, univ. dipl. ing
Mag. Marta Abram
Mag. Mojca Poberžnik, univ. dipl. ing.
Mag. Maja Bauman, univ.dipl.ing
Špela Mojca Korent, univ. dipl.ing.
Alenka Kelc, univ.dipl.ing.
Alenka Ribič, univ.dipl.ing.
Nina Frančič, univ. dipl. biokemik
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