DNA Sensing on a DNA Probe-Modified Electrode Using Ferrocenylnaphthalene Diimide as the Electrochemically Active Ligand

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• 作者：Shigeori Takenaka ; Kenichi Yamashita ; Makoto Takagi ; Yoshihiro Uto ; and Hiroki Kondo
• 刊名：Analytical Chemistry
• 出版年：2000
• 出版时间：March 15, 2000
• 年：2000
• 卷：72
• 期：6
• 页码：1334 - 1341
• 全文大小：109K
• 年卷期：v.72,no.6(March 15, 2000)
• ISSN：1520-6882

文摘

Naphthalene diimide derivative 1 carrying ferrocenylmoieties at the termini of imide substituents binds intactcalf thymus DNA 4 times more strongly than the denatured DNA, and its complex with the intact DNA dissociates 80 times more slowly than that with the denaturedDNA. On the basis of these observations, ligand 1 wasapplied to a probe of electrochemical DNA sensing. Athiol-linked single-stranded DNA probe was immobilizedthrough the S-Au bonding to 20-30 pmol/mm² on a goldelectrode. Following hybridization with the complementary DNA, the electrode was soaked in a solution containing 1 (intercalation step) and then washed with buffer for5 s. The cyclic voltammogram and differential pulsevoltammogram for this electrode gave an electrochemicalsignal due to the redox reaction of 1 that was bound tothe double-stranded DNA on the electrode. Thus, dA₂₀and the yeast choline transport gene were quantitated atthe subpicomole level. The sensitivity of DNA detectionwas improved to 10 zmol by reducing the amount ofimmobilized DNA probe and protecting the uncoveredsurface of the electrode with 2-mercaptoethanol.