Electrochemical Quantitative Analysis of Nucleic Acids Using -Cyclodextrin Modified Gold Electrode

초록

We present an electrochemical biosensor for the analysis of nucleic acids upon hybridization on the -cyclodextrin (-CD)-modified gold electrode. The strategy is based on the following: The 5'-ferrocene-labeled single stranded capture probe DNA (5'-fc-ss-DNA) was incorporated into the cavity of thiolated -CD which was immobilized on the surface of gold electrode. After hybridization of complementary target DNA, hybridized double stranded DNA (ds-DNA) was released from the cavity of -CD. The difference of electrochemical properties on the modified gold electrode was characterized by cyclic voltametry and surface plasmon resonance. We successfully applied this method to the investigation of the sensor responses due to hybridization on various concentrations of applied target DNA. As a result, the label-free electrochemical DNA sensor can detect the target DNA with a detection limit of 1.08 nM. Finally, our method does not require either hybridization indicators or other signalling molecules such as DNA intercalaters which most of electrochemical hybridization detection systems require.

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