DNA Biosensor Based on Self-Assembled Bilayer Lipid Membranes for the Detection of Hydrazines

This article reports a new DNA biosensor strategy for detection of chemicals. This strategy is based on electrochemical monitoring of changes of ion current through a lipid membrane with immobilized DNA probes caused by interaction of these modified BLMs with hydrazine compounds. A self-assembled metal supported bilayer lipid membrane (s-BLM) composed of egg phosphatidyl choline was prepared on a silver metal electrode. The oligomers used were single stranded deoxyribonucleic acids: thymidylic acid icosanucleotide terminated with a C-16 alkyl chain to assist incorporation into s-BLMs (dT20-C16), and deoxyadenylic acid icosanucleotide (dA20). These s-BLMs with incorporated DNA interact with hydrazines, and the s-BLMs display an analytically useful tool for ppb detection levels of hydrazine compounds (i.e., hydrazine, methylhydrazine, dimethylhydrazine and phenylhydrazine). This BLM/DNA biosensor offers a highly sensitive, rapid, and portable device for monitoring these environmentally and toxicologically significant compounds.