D

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Détection des insecticides organophosphorés et
carbamates
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Nerve cell communication Synaptic membrane
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(No Transcript)
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How nerve agents work
Acetyl choline AC receptor AC
esterase Nerve agent

• Nerve agents block the breakdown of
  acetylcholine muscle contracts continuously
• This results in paralysis

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STRATEGY
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STRATEGY
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Amperometric Biosensor
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Screen printed method
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LOW COST PORTABLE SINGLE USE HIGHLY
REPRODUCIBLE SAMPLE HANDLING MASS PRODUCTION NO
SKILLED PERSONNAL FAST DETECTION
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STRATEGY
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Entrapment of AChE in PVA-SbQ
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Immobilisation of AChE in SOL-GEL
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Principle of Metal Affinity Chelate
Ni
Graphite-NTA-Ni
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Principle of Con A
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Principle of Con A
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STRATEGY
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CHOLINESTERASE

• Electric eel
• Bovine erythrocyte
• Torpedo california
• Horse serum
• Drosophila melanogaster

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• CHOLINESTERASE
• Electric eel (98 Biotools)

• Drosophila melanogaster

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Insecticide Electric eel Drosophila melanogaster Factor
Paraoxon 0,29 1,55 5
Azinphos 0,36 33,00 92
Chlorpyrifos oxon 2,85 1135,00 398
Dichlorvos 0,03 1,90 63
Carbaryl 0,07 0,20 3
Omethoate 0,001 0,042 42
Values of Ki in mmole-1.L-1
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Acetylcholinesterase structure
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Engineered cholinesterase
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Insecticide Electric eel Wild Dm Modified Dm
Paraoxon 0,29 5 66
Azinphos 0,36 92 1922
Chlorpyrifos oxon 2,85 398 568
Dichlorvos 0,03 63 300 000
Carbaryl 0,07 3 40
Omethoate 0,03 42 2320
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Detection of carbamate insecticides

• SOURCE OF ENZYME
• Drosophila melanogaster (Dm)

PESTICIDES Pirimicarb Carbaryl Carbofuran
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Detection principle
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ILLUSTRATED PROCEDURE
1. Measurement of the initial current, I0
2. Incubation time 20 min
Igt10
Inhibition(I0-I1)/I0 x 100
Ilt10
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Pirimicarb
1x10-6 8x10-7 5x10-7 3x10-7 1x10-7 7x10-8 4x10-8 2x10-8
AChE-wt 87 68 51 30 13
B3(E69W) 100 69 30 17 12
B12(Y408A) 88 60 27 12
B41(I116V) 90 83 64 48 20 12
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Carbaryl
8x10-7 5x10-7 3x10-7 1x10-7 7x10-8 5x10-8 3x10-8 1x10-8
AChE-wt 73 59 18 10
B3(E69W) 87 75 47 40 13
B12(Y408A) 98 64 40 27 15
B41(I116V) 100 83 55 23 13
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Carbofuran
5x10-7 1x10-7 5x10-8 1x10-8 1x10-8 5x10-9 1x10-9 8x10-10
AChE-wt Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation Useless due to fast reactivation
B3(E69W) 82 74 39 39 10
B12(Y408A) 96 82 67 67 37 11
B41(I116V) 95 65 48 23 11
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Real sample analysis
Standard solutions of the insecticide Tap water Tap water Flat water  Sémillante  Flat water  Sémillante 
Standard solutions of the insecticide directly spiked directly spiked
B3 (E69W) Pirimicarb 10-7 M 30 8 38 3 30
B12 (Y408A) Carbaryl 5x10-8 M 40 8 37 7 42
B41(I116V) Carbofuran 5x10-9 M 48 5 42 8 36
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(No Transcript)
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OP-Prot Sensor
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ILLUSTRATED PROCEDURE
Tested solution If solution still uncolored,
the test is positive. There are inhibiting
substances in the solution
Transfer 10ml to tube 1 yellow
Transfer to tube 2 Blue
Transfer to tube 3 red
Transfer to tube 4 green
Solution to be tested
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2
3
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Control solution insecticide free
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2
3
4


Shake and incubate 15 min.
Shake and incubate 10 min.
Shake and incubate 1 hour.
Shake and incubate 5 to 10 min.
Reference tube has to become yellow, meaning
there is no insecticide
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LIMIT OF DETECTION
COMPOUND WATER (ppb or mg/L) Chlorpyriphos
ethyl 0.1 Paraoxon 1 Parathion 1 Dichlor
vos 1 Malaoxon 1 Malathion 1 Profenofo
s 10 Carbofuran 10 Carbaryl 100 Pirimi
carb 1000
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LIMIT OF DETECTION
COMPOUND WATER (ppb or mg/L) Chlorpyriphos
ethyl 0.1
Paraoxon 1 Parathion 1
Dichlorvos 1
Malaoxon 1 Malathion 1
Profenofos 10 Carbofuran 10 Carbaryl 1
00 Pirimicarb 1000
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(No Transcript)
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OP-Stick Sensor
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LOD
Insecticide OP-Protein Sensor Amperometric biosensor
Chlorpyriphos Ethyl oxon 0.1 ppb 0.05 ppb
Carbofuran 100 ppb 40 ppb
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Toulouse (FRANCE)