DETECTION OF DNA HYBRIDIZATION USING SELF-ASSEMBLED BILAYER-LIPID MEMBRANES (BLMS)

The present work reports the use of self-assembled bilayer lipid membr anes supported on the surface of a metal (s-BLMs) as transducers for t he direct electrochemical monitoring of DNA hybridization. Characteriz ed oligomers based on single stranded deoxyribonucleic acid (ssDNA) th ymidylic acid icosanucleotides that were terminated with C-16 (dT(20)- C-16) and deoxyadenylic acid icosanucleotides (dA(20)) were used for t he hybridization procedure at the lipid membrane surface. The decrease of the ion conductivity observed during the hybridization procedure i s indicative of the formation of the duplex, which may subsequently be excluded from the membrane. The incorporation of nucleic acids into t he lipid matrix was investigated by differential scanning calorimetric (DSC) experiments. The present simple electrochemical biosensor for m onitoring of DNA hybridization was regenerable for multiple cycles of application. This approach provides low detection limits for DNA (a fe w hundreds of fmol), fast response times (on the order of a few minute s), mild conditions of hybridization and capability of analyzing small volumes of sample.