A capacitive field-effect sensor for the direct determination of organophosphorus pesticides
نویسندگان
چکیده
A novel capacitive field-effect sensor for the direct determination of organophosphorus pesticides by the enzyme organophosphorus hydrolase (OPH) is presented. The enzyme OPH hydrolyses organophosphorus compounds catalytically, thus releasing Hþ ions. By means of a silicon-based field-effect sensor, which consists of a layer sequence of Al/p-Si/SiO2 with alternative pH-sensitive materials (Ta2O5, Al2O3 and Si3N4), this pH shift can be recorded directly in a potentiometric measuring arrangement. To obtain the enzyme biosensor, thus the OPH has been immobilised on top of the pH-sensitive layer structure. Typical sensor characteristics, like pH sensitivity, sensitivity towards paraoxon, reversibility of the sensor signal, response time, detection limit, long-term stability and selectivity to various pesticides have been studied. # 2003 Elsevier Science B.V. All rights reserved.
منابع مشابه
Towards a Capacitive Enzyme Sensor for Direct Determination of Organophosphorus Pesticides: Fundamental Studies and Aspects of Development
The realisation of a miniaturised potentiometric enzyme biosensor is presented. The biosensor chip utilises the enzyme organophosphorus hydrolase (OPH) for the direct determination of pesticides. The transducer structure of the sensor chip consists of a pHsensitive capacitive electrolyte-insulator-semiconductor (EIS) structure that reacts towards pH changes caused by the OPH-catalysed hydrolysi...
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