Detection of DNA hybridization using self-assembled bilayer lipid membranes (BLMs)

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