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

Abstract

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 (dT 20 -C 16 ), and deoxyadenylic acid icosanucleotide (dA 20 ). 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.

A biosensor platform for soil management: the case of nitrites

“…Upon the addition, highmagnitude transient signals appear, indicative of the adsorption of the bioelement on the membrane; these signals decrease in both, magnitude and frequency of appearance, and within 10e20 min the membraneebioelement complex stabilizes at a residual (background) current of 5e10 pA . The complex remains stable and functional, i.e., with no observable bioelement leakage or sensitivity decrease, for flow rates up to 20 mL/min , rapid gel-to-liquid phase shiftings and temperatures up to 40 C (Siontorou et al, 1998).…”

“…sBLMs exhibit similar behavior to the suspended membranes, especially as regards bioelement attachment and transduction , although the background current rests much higher, at 10e15 nanoamperes (nA). Conversely, responses to target analytes are manifested as permanent ion current increases (Siontorou and Nikolelis, 1997;Siontorou et al, 1997a) and the discrimination capabilities for similar chemical species are reduced; the sensor provides cumulative responses for classes of substances, such as total triazines (Siontorou et al, 1997b) or total hydrazines (Siontorou et al, 1998) in the sample. Nonetheless, the supported platforms proved robust enough to allow for the analysis of environmental samples and seem more promising for commercialization (Siontorou and Batzias, 2013).…”

“…The optimization of the analytical signal followed the procedure established previously for similar biosensor platforms: s-BLM/ gramicidin sensor for ammonium ion , s-BLM/ haemoglobin sensor for carbon dioxide (Siontorou et al, 1997a), s-BLM sensor for triazines (Siontorou et al, 1997b), and s-BLM/DNA sensor for hydrazines (Siontorou et al, 1998). Investigation followed a tiered approach, focusing on s-BLM platform construction, methemoglobin incorporation and response to nitrites, signal optimization and sensor regeneration; an overview of the investigation and the optimal operational conditions are presented in Table 1.…”

“…It has been previously demonstrated that this s-BLM platform responds to both, increases and decreases of analyte concentration, although it is impossible to totally extract the bioelement from the membrane without destroying the sensor Siontorou et al, 1997a;1997b;1998). In these reports, sensor reversibity could be achieved, to some extent, by gradually removing electrolyte volume from the electrochemical cell and replacing it with analyte-free electrolyte until an acceptable background current was reached.…”

“…In these reports, sensor reversibity could be achieved, to some extent, by gradually removing electrolyte volume from the electrochemical cell and replacing it with analyte-free electrolyte until an acceptable background current was reached. Yet, memory and carryover effects could not be ruled out (Siontorou et al, 1998); thus the authors suggested the use of newly constructed sensors for reliable detections. This, actually, has proved to be time-consuming, laborious, and impractical with large sample rates.…”