Linked Life Data

15967350

Source:http://linkedlifedata.com/resource/pubmed/id/15967350

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-6-21
pubmed:abstractText
The research on our flow-injection, label-free, non-faradaic impedimetric immunosensor for interferon-gamma (IFN-gamma) has been extended. The sensor is prepared by immobilization of anti-IFN-gamma antibodies on a self-assembled monolayer (SAM) of acetylcysteine, deposited on polycrystalline gold. A multi-frequency impedance method is described, which allows time-resolved measurement of Nyquist plots. To these plots, an equivalent circuit was fitted, which is discussed in terms of a two-layer structure (inner and outer layer) of the interfacial region. Because binding of IFN-gamma mainly causes a decrease of Q (a constant-phase element), this element is considered as the outer layer. Several aspects of the impedimetric sensor response are studied, including the dependence on detection frequency, target concentration and applied dc potential. For quantitative detection of IFN-gamma, an optimum of the signal-to-noise (S/N) ratio of the out-of-phase impedance component (Z'') was found at about 100 Hz. At a dc-potential of +0.2 V versus a saturated calomel reference electrode, the sensor response is higher than at 0.0 V. Logarithmic dose-response curves of IFN-gamma in the concentration range of 10(-18) to 10(-9) M were obtained using two procedures: by successive injections over a single electrode, and by using freshly prepared electrodes for each measurement. Using the latter method, the repeatability is impaired. The need for in situ complementary techniques for a correct interpretation of the studied parameters is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0956-5663
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49-59
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
On the response of a label-free interferon-gamma immunosensor utilizing electrochemical impedance spectroscopy.
pubmed:affiliation
Department of Biomedical Analysis, Faculty of Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.
pubmed:publicationType
Journal Article, Validation Studies