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Development of a biosensor for urea assay based on amidase inhibition, using an ion-selective electrode

2011-08Journal article Open access
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dc.contributor.authorBarbosa, Ana Rita Dantas Balsemão
dc.contributor.authorKarmali, Amin
dc.date.accessioned2013-01-31T17:14:17Z
dc.date.available2013-01-31T17:14:17Z
dc.date.issued2011-08
dc.description.abstractA biosensor for urea has been developed based on the observation that urea is a powerful active-site inhibitor of amidase, which catalyzes the hydrolysis of amides such as acetamide to produce ammonia and the corresponding organic acid. Cell-free extract from Pseudomonas aeruginosa was the source of amidase (acylamide hydrolase, EC 3.5.1.4) which was immobilized on a polyethersulfone membrane in the presence of glutaraldehyde; anion-selective electrode for ammonium ions was used for biosensor development. Analysis of variance was used for optimization of the biosensorresponse and showed that 30 mu L of cell-free extract containing 7.47 mg protein mL(-1), 2 mu L of glutaraldehyde (5%, v/v) and 10 mu L of gelatin (15%, w/v) exhibited the highest response. Optimization of other parameters showed that pH 7.2 and 30 min incubation time were optimum for incubation ofmembranes in urea. The biosensor exhibited a linear response in the range of 4.0-10.0 mu M urea, a detection limit of 2.0 mu M for urea, a response timeof 20 s, a sensitivity of 58.245 % per mu M urea and a storage stability of over 4 months. It was successfully used for quantification of urea in samples such as wine and milk; recovery experiments were carried out which revealed an average substrate recovery of 94.9%. The urea analogs hydroxyurea, methylurea and thiourea inhibited amidase activity by about 90%, 10% and 0%, respectively, compared with urea inhibition.por
dc.identifier.citationBARBOSA Rita; KARMALI, Amin - Development of a biosensor for urea assay based on amidase inhibition, using an ion-selective electrode. Biocatalysis and Biotransformation. ISSN 1024-2422. Vol. 29, n.º 4 (2011) p. 130-140.por
dc.identifier.issn1024-2422
dc.identifier.urihttp://hdl.handle.net/10400.21/2144
dc.language.isoengpor
dc.peerreviewedyespor
dc.publisherInforma Healthcarepor
dc.subjectIon-selective electrodepor
dc.subjectAliphatic amidasepor
dc.subjectUrea biosensorpor
dc.subjectPseudomonas-aeruginosapor
dc.subjectEthyl carbamatepor
dc.subjectKinetic-propertiespor
dc.subjectRisk assessmentpor
dc.subjectMilk ureapor
dc.subjectEnzymepor
dc.subjectOrganophosphoruspor
dc.subjectCholinesterasepor
dc.subjectPesticidepor
dc.subjectNitrogenpor
dc.titleDevelopment of a biosensor for urea assay based on amidase inhibition, using an ion-selective electrodepor
dc.typejournal article
dspace.entity.typePublication
oaire.citation.conferencePlaceLondonpor
oaire.citation.endPage140por
oaire.citation.issue4por
oaire.citation.startPage130por
oaire.citation.titleBiocatalysis and Biotransformationpor
oaire.citation.volume29por
person.familyNameKarmali
person.givenNameAmin
person.identifier.orcid0000-0003-0419-401X
person.identifier.ridE-4787-2011
person.identifier.scopus-author-id6603778216
rcaap.rightsrestrictedAccesspor
rcaap.typearticlepor
relation.isAuthorOfPublication23975b4b-3234-4139-9675-89ea6f9a2332
relation.isAuthorOfPublication.latestForDiscovery23975b4b-3234-4139-9675-89ea6f9a2332

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