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Affinity biosensors based on solid supported lipid membranes. Their structure, physical properties and dynamics

1998; Elsevier BV; Volume: 47; Issue: 1 Linguagem: Inglês

10.1016/s0302-4598(98)00162-7

1872-8049

Tibor Hianik, V.I. Passechnik, L. Sokolı́ková, Maja Šnejdárková, Branislav Sivak, Martin Fajkus, Sergey A. Ivanov, Milan Fránek,

Lipid Membrane Structure and Behavior

The paper describes results of study of physical properties of novel affinity biosensor based on self-assembled metal supported systems of biotinylated bilayer lipid membranes (s-BLM). In this biosensor, avidin modified monoclonal antibody originating from E2/G2 clone (A-MAb) was used as the antibody and 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide as the antigen (Ag) to provide an immunological interaction that could be transduced by the presented s-BLM sensor. An increase of membrane conductance, κ, an increase of elasticity modulus in the direction perpendicular to the membrane plane, E⊥ and decrease of membrane capacitance, C, were experimentally proved by the addition of Ag to the s-BLM and used as a sensor response. The analysis of experimental results showed that interaction of Ag with the A-MAb resulted in changes of membrane mechanical properties, which might be connected with the induction of conformational changes in the A-MAb complex after binding with Ag. Binding of A-MAb to the free standing BLM as well as interaction of 2,4-D with A-MAb modified BLM resulted in increase of relaxation times of dipole moments reorientation as revealed from capacitance relaxation experiments. The physical properties of the s-BLM depend on the metal support on which the membrane is formed. This has been proved by comparison of the properties of s-BLM formed on the tip of freshly cut polymer coated stainless steel wire and on thin gold layer.