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Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/35553
Title: 
Evaluation of a highly sensitive amperometric biosensor with low cholinesterase charge immobilized on a chemically modified carbon paste electrode for trace determination of carbamates in fruit, vegetable and water samples
Author(s): 
Institution: 
  • Universidade Federal do Maranhão (UFMA)
  • CSIC
  • Univ Barcelona
  • Universidade Estadual Paulista (UNESP)
ISSN: 
0003-2670
Abstract: 
A highly sensitive amperometric biosensor for determination of carbamate pesticides directly in water, fruit and vegetable samples has been evaluated, electrochemically characterized and optimized. The biosensor strip was fabricated in screen printed technique on a ceramic support using silver-based paste for reference electrode, and platinum-based paste for working and auxiliary electrodes. The working electrode was modified by a layer of carbon paste mixed with cobalt(II) phthalocyanine and acetylcellulose. Cholinesterase (ChE) enzymes with low enzymatic charge were immobilized on this layer. The operational simplicity of the biosensor consists in that a small drop (similar to 50 mu l) of substrate or sample is deposited on a horizontally positioned biosensor strip representing the microelectrochemical cell. The working potential of the biosensor was 370 mV versus Ag/AgI on a ship reference electrode preventing the interference of electroactive species which are oxidable at more positive potentials. The biosensor was applied to investigate the degradation of two reference ChE inhibitors in freeze dried water under different storage conditions and for direct determination of some N-methylcarbamates (NMCs) in fruit and vegetable samples at ppb concentration levels without any sample pretreatment. A comparison of the obtained results for the total carbamate concentration was done against those obtained using HPLC measurements. (C) 1999 Elsevier B.V. B.V. All rights reserved.
Issue Date: 
8-Nov-1999
Citation: 
Analytica Chimica Acta. Amsterdam: Elsevier B.V., v. 399, n. 1-2, p. 37-49, 1999.
Time Duration: 
37-49
Publisher: 
Elsevier B.V.
Keywords: 
  • amperometric biosensor
  • cholinesterase-based biosensor
  • HPLC analysis
  • carbamates
  • fruit samples
  • vegetable samples
Source: 
http://dx.doi.org/10.1016/S0003-2670(99)00574-7
URI: 
Access Rights: 
Acesso restrito
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/35553
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

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