Peer Reviewed: Detecting DNA Hybridization and Damage

Carbon and gold electrodes as electrochemical transducers for DNA hybridisation sensors

“…Use of this approach can lead to probe structure flexibility with respect to change in its conformation when hybridisation take place (Yang et al, 1997). Random covalent binding of DNA to electrode surfaces, involving chemical modification of the bases, decreases the specificity of the recognition layer and therefore is not recommended (Palecek and Fojta, 2001). Self-assembly provide one of the most elegant approaches to obtain well defined and organised surfaces that can be an excellent platform for biosensor applications.…”

“…Two classes of intercalators, bis-and threading intercalators, were particularly interesting as new redox indicators. The natural occurring bis-intercalator echinomycin, an antibiotic and antitumor agent, was reported to bind dsDNA more tightly than usual indicators (Palecek and Fojta, 2001). …”

“…Recent progresses in the development of electrochemical DNA-hybridisation biosensors have been summarised in some excellent reviews (Pividori et al, 2000;Yang et al, 1997;Wang, 2000;Palecek and Fojta, 2001;Palecek, 2002). Hence, this review will be focused on electrochemical DNA biosensors and sensors developed using carbon and gold electrodes as the transducer.…”

Two‐Surface Strategy in Electrochemical DNA Hybridization Assays: Detection of Osmium‐Labeled Target DNA at Carbon Electrodes

“…However, intrinsic DNA electrochemical signals are in general irreversible and occur at rather extreme potentials, close to background discharge at both mercury and carbon electrodes. For these reasons DNA complexation or derivatization techniques involving electroactive markers are being developed (reviewed in [2,3]). These techniques employ species exhibiting i) well-pronounced electrochemistry at less extreme potentials, involving reversible or catalytic electrode processes, and/or ii) non-covalent or covalent structure-selective interactions with DNA.…”

“…This system works well with target synthetic ODNs of about the same lengths as the capture probe. When real, substantially longer target DNAs (PCR products, plasmid, viral or chromosomal DNAs) are analyzed, sensitivity and specificity of the assay are usually insufficient [2,3,25]. The main difficulties arise from nonspecific DNA adsorption, and considerable interactions of redox indicators with the former or with the singlestranded hybridization probe, etc.…”