A. Bardea et al., Amplified electronic transduction of oligonucleotide interactions: novel routes for Tay-Sachs biosensors, ANALYT CHIM, 385(1-3), 1999, pp. 33-43
Two different configurations for the amplified microgravimetric analysis of
oligonucleotides (DNA) are presented. A thiol-tagged oligonucleotide, (1),
is assembled on a Au-quartz electrode, and the complementary oligonucleoti
de (2) is microgravimetrically sensed by the crystal. Formation of the ds-o
ligonucleotide assembly is amplified using mouse anti-dsDNA antibody and go
at anti-mouse Fc antibody. Alternatively, a biotin-labeled oligonucleotide,
(4), is used to form the ds-oligonucleotide, Biotin is used to amplify the
formation of the ds-complex. An electrochemical method, using cytochrome c
as redox probe, to assay the formation of the ds-oligonucleotide assembly,
is described. The 5'-carboxylic acid-functionalized oligonucleotide (5) is
coupled to a cystamine monolayer associated with an Au-electrode. The elec
trostatic attraction of cytochrome c to the ds-oligonucleotide complex faci
litates the interfacial electron transfer to cytochrome c. Formation of the
ds-oligonucleotide assembly is detected electrochemically using differenti
al pulse voltammetry. (C) 1999 Elsevier Science B.V. All rights reserved.