[Flow injection biosensor based on the immobilized AChE].
A biosensor based on the flow injection system was constructed with the immobilized AChE from Scomberomorus niphonius (Curier) as identification element and a pH electrode as transducer. When phosphate buffer was used as carrier liquid, a good reproducibility (RSD = 1.427% , n=10) of the biosensor response was obtained after the substrate was injected repetitively. After an incubation time of 20 min, the calibration graph to methyl-parathion is linear (r = 0.9986) when its concentration ranges from 4.29 x 10(-10) mol x L(-1) to 4.29 x 10(-8) mol x L(-1) , and the detection limit is 1.3 x 10(-10) mol x L(-1). However, the sensitivity of this biosensor to methyl-parathion when using clean seawater as carrier liquid is not as good as that using phosphate buffer. But after preoxidation of methyl-parathion with NaClO as oxidant, the detection limit of the biosensor to methyl-parathion in seawater can be improve to 2.16 x 10(-7) mol x L(-1).
Zhu
Xiao-shan
XS
College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. zxsgx1977@yahoo.com.cn
Meng
Fan-ping
FP
Zhu
Lin
L
He
Dong-hai
DH
D000110:Acetylcholinesterase / Q000378:metabolism*; D015374:Biosensing Techniques; D004563:Electrochemistry; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004800:Enzymes, Immobilized / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000032:analysis*; D010575:Pesticides / Q000032:analysis; D015203:Reproducibility of Results; D012623:Seawater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004800:Enzymes, Immobilized; D009943:Organophosphorus Compounds; D010575:Pesticides; D014874:Water Pollutants, Chemical; D000110:Acetylcholinesterase