Electrochemical Telomerase Assay with Ferrocenylnaphthalene Diimide as a Tetraplex DNA-Specific Binder

Abstract

Spectroscopic studies revealed that ferrocenylnaphthalene diimide (1) can bind to tetraplex DNA at high potassium ion concentration. The tetraplex DNA was stabilized by the binding of 1, and this effect was larger than that of any other tetraplex stabilizers, which are known as a telomerase inhibitor. Quantitative analysis with circular dichroism and a quartz crystal microbalance strongly suggested a 3:1 binding stoichiometry of 1 to the tetraplex DNA. The telomere sequence could be extended by telomerase with the telomerase substrate primer on the surface of an electrode as proven by an increased current signal of 1 bound to the tetraplex DNA formed on the electrode. This is the first example of electrochemical detection of telomerase activity without relying on PCR.

Telomere and Telomerase in Cancer

“…However, the positive ratios of detection of telomerase vary in sedimented cells obtained from secretion, washing, brushing samples, etc. Electrochemical telomerase assay (ECTA) is another newly emerged technique to detect telomerase activity in biological samples [92]. It is comparatively simple and rapid PCR-free method.…”

Highly sensitive DNA detection and point mutation identification: an electrochemical approach based on the combined use of ligase and reverse molecular beacon

“…Among various methods, electrochemical analysis has shown great promise and drawn much attention because of its simplicity, high sensitivity, and compatibility with microfabrication technology [Whittemore et al, 1999;Kertesz et al, 2000;Boon et al, 2000;Alfonta et al, 2001;Ozkan et al, 2002;Kim et al, 2003;Wang and Liu, 2003;Wong and Gooding, 2003;Kerman et al, 2004;Zhang et al, 2004;Liu et al, 2005a;Tansil et al, 2005]. In particular, ferrocene (Fc) moieties have been shown to be extremely useful for electrochemical detection of telomerase activity, DNA hybridization, and protein binding, owing to the versatility of synthesized various Fc derivatives and the excellent reversibility of redox reaction involved, as well as the stability during DNA synthesis [Yu et al, 2001;Kim et al, 2004;Gibbs et al, 2005;Sato et al, 2005;Le Floch et al, 2006]. Recently, the flexibility of the short DNA, the dynamics of electron transport within DNA monolayer, and the storage stability of self-assembled monolayer used for fabricating electrochemical DNA (E-DNA) sensors have been explored based on the conformation change of a single-stranded DNA modified with a redox-active moiety [Anne et al, 2003;Anne and Demaille, 2006;Lai et al, 2006].…”

Ferrocenylnaphthalene Diimide-based Electrochemical Ribonuclease Assay

“…[7][8][9] Electrochemistry is generally expected to achieve high-sensitive analysis with an inexpensive, compact instrument; this technique has been applied to DNA detection. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Electrochemical DNA analysis so far reported is briefly grouped into two methods based on the ways to be used for electrochemically active labeling of DNA [10][11][12][13][14][15] and an electrochemically active DNA indicator. [7][8][9][16][17][18][19][20][21] Highly sensitive DNA detection was achieved in both methods.…”

“…[7][8][9][16][17][18][19][20][21] Highly sensitive DNA detection was achieved in both methods. An electrochemical DNA enzyme assay has also been reported in DNA polymerase, 14 telomerase, 8 DNase I, 15 and S1 nuclease. 13 However, an electrochemical RNase assay has not yet been reported to the best of our knowledge.…”