Determination of organophosphorus and carbamate pesticides using a biosensor based on a polishable, 7,7,8,8-tetracyanoquinodimethane-modified, graphite-epoxy biocomposite

Daniel Martorell, Francisco Céspedes, Esteve Martínez-Fàbregas, Salvador Alegret

Research output: Contribution to journalArticleResearchpeer-review

82 Citations (Scopus)

Abstract

An amperometric biosensor for the determination of organophosphorus and carbamate pesticides is described. The biosensor is based on robust, polishable and easily machinable biocomposites containing graphite powder, a non-conducting epoxy resin, the electronic mediator 7,7,8,8-tetracyanoquinodimethane (TCNQ) and the enzyme acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) immobilized on aminated silica particles. Determinations were done with acetylthiocholine (ATCh) or butyrylthiocholine (BTCh) as substrate. Thiocholine produced by enzymatic hydrolysis is oxidized electrocatalytically. The biosensor operates at a potential of 300 mV vs. Ag/AgCl in a pH buffered solution with 0.1 M phosphate and 0.1 M KCl. The decrease rate of the steady-state current after the addition of pesticides was used for the determination. The materials employed in the construction of the reported biosensors allow for a prolonged use of the device if a slight polish of the surface is performed from time to time.
Original languageEnglish
Pages (from-to)305-313
JournalAnalytica Chimica Acta
Volume337
Issue number3
DOIs
Publication statusPublished - 30 Jan 1997

Keywords

  • 7,7,8,8-tetracyanoquinodimethane
  • Biosensor
  • Carbamate pesticides
  • Cholinesterase immobilization
  • Cholinesterase-based biosensor
  • Graphite-epoxy biocomposite
  • Organophosphorus pesticides

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