Abstract:

The base pair stack within a DNA duplex can transport charge over long distances. The π-stacked base pairs provide an effective medium for long distance charge transport in DNA molecules. The DNA-mediated charge transport is extremely sensitive to the DNA sequence. This sensitivity can be used to fabricate electrochemical DNA biosensors for single base mismatch sensing. Polyamides are DNA recognition molecules which can bind to the minor groove in DNA to form a DNA/polyamide complex with high affinity and specificity. Polyamide molecules with the nitro group are used as an electrochemically active probe for DNA biosensors. The electrochemical properties of the nitro-polyamide was investigated on a DNA self-assembly electrode. The results indicated that the electrochemical response was enhanced intensitively, and the polyamide can be used as a probe to detect a single base pair mismatch in DNA.

Key words: Biosensor, Electrochemistry, Polyamide, DNA, Mismatch