Citation:
Frank Davis, Alexy V. Nabok and Seamus P.J. Higson, Species differentiation by DNA-modified carbon electrodes using an ac impedimetric approach, Biosensors and Bioelectronics, Volume 20, Issue 8, Selected Papers from the Eighth World Congress on Biosensors, Part I, 15 February 2005, Pages 1531-1538.
Abstract:
A simple and novel electrochemical biosensor based approach is described for
differentiating between differing species of fish on the basis of DNA
hybridisation events. Screen-printed carbon electrodes modified with a variety
of polymers were used to immobilise commercially available DNA in a single-
stranded form. AC impedimetric measurements were firstly carried out on these
systems and then upon exposure to single-stranded DNA solutions. When the
electrode and solution DNA were complementary, a large drop in impedance was
measured; this did not occur for non-matching DNA exposures. DNA hybridisation
sensors for closely related species of fish were in the first instance developed
as a demonstration for this approach. Species of fish such as herrings and
salmon could be differentiated by this method. This sensor format offers great
promise for many DNA hybridisation applications and lends itself to mass
fabrication due to the simplicity and inexpensiveness of the materials and
methods used. The hybridisation results were confirmed by use of ellipsometry to
measure the characteristics of similar films deposited on silicon substrates.
