Article ID Journal Published Year Pages File Type
869639 Biosensors and Bioelectronics 2007 7 Pages PDF
Abstract

The application of electrochemical techniques for DNA detection is motivated by their potential to detect hybridisation events in a more rapid, simplistic and cost-effective manner compared to conventional optical assays. Here, we present an electrochemical DNA sensor for the specific and quantitative detection of single-stranded DNA (ssDNA). Probe oligonucleotides were immobilised onto thin gold film electrodes by a 5′-thiol-linker. Hybridisation was detected by means of the electroactive redox-marker methylene blue (MB) covalently attached to the 5′-end of the target ssDNA and voltammetric techniques. MB-labeled target ssDNA was recognised down to 30 pmol. By application of a competitive binding assay, non-labeled ssDNA was detected down to 3 pmol. In addition, the DNA-modified electrodes were capable of sensing single base-pair mismatches at different positions within the sequence of the hybridised double-stranded DNA (dsDNA).

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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