Amperometric determination of pesticides using a biosensor based on a polishable graphie-epoxy biocomposite

✍ Scribed by D. Martorell; F. Céspedes; E. Martínez-Fàbregas; S. Alegret

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 475 KB
• Volume: 290
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)80121-5

✦ Synopsis

The determination of organophosphorus and carbamate pesticides was carried out using an amperometric transducer based on a robust, polishable and easily machinable biocomposite. The biocomposite material contains graphite powder, a non-conducting epoxy resin and acetylcholinesterase. The enzyme retains its bioactivity in the rigid epoxy-graphite matrix. Measurements were carried out with acetylthiocholine as a substrate. Thiocholine produced by enzymatic hydrolysis was oxidized electrochemically at 700 mV (vs. Ag/AgCl in pH 7.0 buffered solution with 0.1 M phosphate and 0.1 M KCl). The decrease rate of substrate steady-state current after the addition of pesticide was used for evaluation. The method of construction allows for the repetitive use of the electrode. Simple polishing procedures are used to regenerate the bioactive transducer surface.