A minisensor for the rapid screening of atenolol in pharmaceutical preparations based on surface-stabilized bilayer lipid membranes with incorporated DNA.

This work describes an electrochemical technique that is suitable for the rapid and sensitive screening of atenolol based on surface-stabilized bilayer lipid membranes (s-BLMs) composed from egg phosphatidylcholine (PC). The interactions of atenolol with s-BLMs produced electrochemical ion current increases that reproducible appeared within a few seconds after the exposure of the membranes to the drug. The current signal increase was related to the concentration of atenolol in bulk solution in the micromolar range. The present lipid film-based sensor provided fast response (i.e. on the order of a few seconds) to alterations of atenolol concentration (20 to 200 micro M) in electrolyte solution. ssDNA incorporated into s-BLMs can interact with atenolol, and decreased the detection limit of this drug by one order of magnitude. The oligomers used were single stranded deoxyribonucleic acids: thymidylic acid icosanucleotide terminated with a C-16 alkyl chain to assist incorporation into s-BLMs (5'-hexadecyl-deoxythymidylic acid icosanucleotide, dT(20)-C(16)). The electrochemical transduction of the interactions of atenolol with s-BLMs was applied in the determination of these compounds in pharmaceutical preparations by using the present minisensor.