Electrochemiluminescent DNA sensor based on controlled Zn-mediated grafting of diazonium precursors.

Mabel Torréns, Mayreli Ortiz, Diego Bejarano-Nosas, Ciara K O'Sullivan

Index: Anal. Bioanal. Chem 407 , 5579-86, (2015)

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Abstract

Controlled Zn-mediated grafting of a thin layer of a diazonium salt was used to functionalise a carbon electrode with ruthenium(II)-tris-bipyridine (Ru)-labelled DNA for use as a capture probe in an electrochemiluminescent genosensor. A secondary reporter probe was labelled with a ferrocene (Fc) molecule, and in the presence of the single-stranded DNA target a genocomplex formed, where the Fc-label effectively quenched the electrochemiluminescence of the signal emitted from the Ru-label. The spacing of the labels for maximum sensitivity and minimum detection limit was optimised, and the signal reproducibility and stability of the method was established.