Linked Life Data

18936839

Source:http://linkedlifedata.com/resource/pubmed/id/18936839

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2008-10-21
pubmed:abstractText
Redox cycling of enzymatically amplified electroactive species has been widely employed for high signal amplification in electrochemical biosensors. However, gold (Au) electrodes are not generally suitable for redox cycling using a reducing (or oxidizing) agent because of the high background current caused by the redox reaction of the agent at highly electrocatalytic Au electrodes. Here we report a new redox cycling scheme, using nicotinamide adenine dinucleotide (NADH), which can be applied to Au electrodes. Importantly, p-aminophenol (AP) redox cycling by NADH is achieved in the absence of diaphorase enzyme. The Au electrodes are modified with a mixed self-assembled monolayer of mercaptododecanoic acid and mercaptoundecanol, and a partially ferrocenyl-tethered dendrimer layer. The self-assembled monolayer of long thiol molecules significantly decreases the background current of the modified Au electrodes, and the ferrocene modification facilitates easy oxidation of AP. The low amount of ferrocene on the Au electrodes minimizes ferrocene-mediated oxidation of NADH. In sandwich-type electrochemical immunosensors for mouse immunoglobulin G (IgG), an alkaline phosphatase label converts p-aminophenylphosphate (APP) into electroactive AP. The amplified AP is oxidized to p-quinoneimine (QI) by electrochemically generated ferrocenium ion. NADH reduces QI back to AP, which can be re-oxidized. This redox cycling enables a low detection limit for mouse IgG (1 pg mL(-1)) to be obtained.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1364-5528
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1599-604
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
An electrochemical immunosensor using p-aminophenol redox cycling by NADH on a self-assembled monolayer and ferrocene-modified Au electrodes.
pubmed:affiliation
Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't