title: Electrochemical biosensor for carbofuran pesticide based on esterases from Eupenicillium shearii FREI-39 endophytic fungus.
abstract: In this work, a biosensor was constructed by physical adsorption of the isolated endophytic fungus Eupenicillium shearii FREI-39 esterase on halloysite, using graphite powder, multi-walled carbon nanotubes and mineral oil for the determination of carbofuran pesticide by inhibition of the esterase using square-wave voltammetry (SWV). Specific esterase activities were determined each 2 days over a period of 15 days of growth in four different inoculation media. The highest specific activity was found on 6th day, with 33.08 U on PDA broth. The best performance of the proposed biosensor was obtained using 0.5 U esterase activity. The carbofuran concentration response was linear in the range from 5.0 to 100.0 µg L(-1) (r=0.9986) with detection and quantification limits of 1.69 µg L(-1) and 5.13 µg L(-1), respectively. A recovery study of carbofuran in spiked water samples showed values ranging from 103.8±6.7% to 106.7±9.7%. The biosensor showed good repeatability and reproducibility and remained stable for a period of 20 weeks. The determination of carbofuran in spiked water samples using the proposed biosensor was satisfactory when compared to the chromatographic reference method. The results showed no significant difference at the 95% confidence level with t-test statistics. The application of enzymes from endophytic fungi in constructing biosensors broadens the biotechnological importance of these microorganisms.
authors.affiliation: Departamento de Química, Grupo de Eletroquímica e Novos Materiais, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Gregory Ferreira
authors.initials: GF
authors.lastname: Grawe
authors.affiliation: Departamento de Química, Grupo de Eletroquímica e Novos Materiais, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Tássia Regina
authors.initials: TR
authors.lastname: de Oliveira
authors.affiliation: Departamento de Botânica e Ecologia, Laboratório de Biotecnologia e Ecologia Microbiana, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Esther
authors.initials: E
authors.lastname: de Andrade Narciso
authors.affiliation: Departamento de Química, Grupo de Eletroquímica e Novos Materiais, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Sally Katiuce
authors.initials: SK
authors.lastname: Moccelini
authors.affiliation: Departamento de Química, Grupo de Eletroquímica e Novos Materiais, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Ailton José
authors.initials: AJ
authors.lastname: Terezo
authors.affiliation: Departamento de Botânica e Ecologia, Laboratório de Biotecnologia e Ecologia Microbiana, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil.
authors.forename: Marcos Antonio
authors.initials: MA
authors.lastname: Soares
authors.affiliation: Departamento de Química, Grupo de Eletroquímica e Novos Materiais, Universidade Federal de Mato Grosso, 78060-900, Cuiabá, MT, Brazil. Electronic address: mcterezo@ufmt.br.
authors.forename: Marilza
authors.initials: M
authors.lastname: Castilho
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002235:Carbofuran / Q000737:chemistry / Q000302:isolation & purification*; D004800:Enzymes, Immobilized / Q000737:chemistry; D004950:Esterases / Q000737:chemistry*; D055324:Eupenicillium / Q000737:chemistry / Q000201:enzymology; D037742:Nanotubes, Carbon / Q000737:chemistry; D010575:Pesticides / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D010575:Pesticides; D004950:Esterases; D002235:Carbofuran
keywords: Biosensor; Carbofuran; E. shearii; Endophytic fungi