Sensitive detection of pesticides using amperometric sensors based on cobalt phthalocyanine-modified composite electrodes and immobilized cholinesterases
- 1 January 1992
- journal article
- Published by Elsevier BV in Biosensors and Bioelectronics
- Vol. 7 (5), 335-343
- https://doi.org/10.1016/0956-5663(92)85029-a
Abstract
The determination of organophosphate and carbamate pesticides was carried out using cobalt phthalocyanine-modified carbon epoxy composite electrodes coupled with acetylcholinesterase or butyrylcholinesterase. Covalent immobilization of enzymes on Immobilon membranes or nylon nets was examined; the highest sensitivity to inhibitors was found for the nylon net containing low enzyme loading and this was subsequently used for the construction of an amperometric biosensor for pesticides. Analyses were done using acetyl- or butyrylthiocholine as substrates; thiocholine produced by hydrolysis in the enzyme membrane was electrochemically oxidized at +300 mV (vs. Ag/AgCl reference). The decrease of substrate steady-state current caused by the addition of pesticide was used for evaluation. With this approach, 1.5 and 8.4 μg 1−1 of paraoxon and heptenophos, respectively, can be detected in less than 3 min. These detection limits are similar as those obtained when analyses were performed using free cholinesterase and 10 min incubation with inhibitor.This publication has 16 references indexed in Scilit:
- Chemically modified electrodes for the determination of sulphydryl compoundsAnalytica Chimica Acta, 1991
- Printed amperometric sensor based on TCNQ and cholinesteraseBiosensors and Bioelectronics, 1991
- Determination of organophosphate and carbamate pesticides using a cobalt phthalocyanine-modified carbon paste electrode and a cholinesterase enzyme membraneAnalytica Chimica Acta, 1991
- Determination of Organophosphorus and Carbamic Pesticides with a Choline and Acetylcholine Electrochemical BiosensorAnalytical Letters, 1991
- Electrocatalytic amperometric detection at polymeric cobalt phthalocyanine electrodesElectroanalysis, 1991
- Flow-injection determination of paraoxon by inhibition of immobilized acetylcholinesteraseAnalytica Chimica Acta, 1990
- Exchangeable immobilized enzyme reactor for enzyme inhibition tests in flow-injection analysis using a magnetic device. Determination of pesticides in drinking waterAnalytica Chimica Acta, 1990
- Characterization and semiquantitative estimation of organophosphorus compounds based on inhibition of cholinesterasesAnalytica Chimica Acta, 1989
- Enzyme electrodes with improved mechanical and analytical characteristics obtained by binding enzymes to nylon netsAnalytica Chimica Acta, 1983
- Enzymatic methods of analysis : Trace analysis of various pesticides with insect cholinesterasesAnalytica Chimica Acta, 1970