Biosensor for direct determination of organophosphate nerve agents. 1. Potentiometric enzyme electrode
| Autor: | Priti Mulchandani, Ashok Mulchandani, Irina Kaneva, Wilfred Chen |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Immobilized enzyme
Potentiometric titration Biomedical Engineering Biophysics Enzyme electrode Biosensing Techniques Buffers Nervous System pH meter chemistry.chemical_compound Organophosphorus Compounds Enzyme Stability Electrochemistry medicine Animals Bovine serum albumin HEPES Chromatography Paraoxon biology Aryldialkylphosphatase Chemistry Esterases Temperature Serum Albumin Bovine General Medicine Hydrogen-Ion Concentration Cross-Linking Reagents Glutaral Potentiometry biology.protein Cattle Biosensor Biotechnology medicine.drug |
| Zdroj: | Biosensors and Bioelectronics. 14:77-85 |
| ISSN: | 0956-5663 |
| DOI: | 10.1016/s0956-5663(98)00096-7 |
| Popis: | A potentiometric enzyme electrode for the direct measurement of organophosphate (OP) nerve agents was developed. The basic element of this enzyme electrode was a pH electrode modified with an immobilized organophosphorus hydrolase (OPH) layer formed by cross-linking OPH with bovine serum albumin (BSA) and glutaradehyde. OPH catalyses the hydrolysis of organophosphorus pesticides to release protons, the concentration of which is proportional to the amount of hydrolysed substrate. The sensor signal and response time was optimized with respect to the buffer pH, ionic concentration of buffer, temperature, and units of OPH immobilized using paraoxon as substrate. The best sensitivity and response time were obtained using a sensor constructed with 500 IU of OPH and operating in pH 8.5, 1 mM HEPES buffer. Using these conditions, the biosensor was used to measure as low as 2 microM of paraoxon, ethyl parathion, methyl parathion and diazinon. The biosensor was completely stable for at least one month when stored in pH 8.5, 1 mM HEPES + 100 mM NaCl buffer at 4 degrees C. |
| Databáze: | OpenAIRE |
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