Method and device for studying transport of an agent across a bilayer membrane in bioanalytical sensor applications

Abstract

The present invention provides a method for studying transport of an agent across a membrane comprising the steps a) providing at least one surface with a bilayer structure tethered to the surface, said bilayer structure comprising a detection volume, b) contacting the bilayer with at least one agent to be analysed, and c) detecting a change in refractive index in the detection volume resulting from transportation of the agent across the membrane. Further there is provided a device comprising a) at least one surface, b) at least one bilayer structure tethered to the surface, and c) at least one sensor capable of detecting a change in refractive index in a detection volume, wherein the bilayer structure encloses a first volume of the detection volume and wherein the volume not enclosed by the bilayer structure but within the detection volume is a second volume and wherein the ratio between the first volume and second volume is above about 0.001.

1 . A method for studying transport of an agent across a membrane comprising the steps of:
 a. providing at least one surface with a bilayer structure tethered to the surface, said bilayer structure comprising a detection volume,   b. contacting the bilayer with at least one agent to be analysed, and   c. detecting a change in refractive index in the detection volume resulting from transportation of the agent across the membrane.   
     
     
         2 . The method according to  claim 1 , comprising detecting a change in refractive index with at least one sensor selected from the group consisting of a surface plasmon resonance sensor, an ellipsometry sensor, and an optical waveguide laser spectroscopy sensor. 
     
     
         3 . The method according to  claim 1  wherein at least one entity selected from the group consisting of a membrane protein, and an ionophore is associated with the bilayer structure. 
     
     
         4 . The method according to  claim 1 , wherein the bilayer structure comprises at least one liposome. 
     
     
         5 . The method according to  claim 4 , wherein at least one liposome is tethered to the surface with a spacer molecule. 
     
     
         6 . The method according to  claim 1 , wherein the bilayer structure comprises at least two layers of liposomes. 
     
     
         7 . The method according to  claim 1 , comprising measuring the refractive index in a volume enclosed by the bilayer structure. 
     
     
         8 . The method according to  claim 1 , wherein the bilayer structure encloses a first volume of the detection volume and wherein the volume not enclosed by the bilayer structure but within the detection volume is a second volume and wherein the ratio between the first and second volumes is optimised for measurement of refractive index of the first volume. 
     
     
         9 . A device comprising
 a. at least one surface,   b. at least one bilayer structure tethered to the surface, and   c. at least one sensor capable of detecting a change in refractive index in a detection volume, wherein the bilayer structure encloses a first volume of the detection volume and wherein the volume not enclosed by the bilayer structure but within the detection volume is a second volume and wherein the ratio between the first volume and second volume is above about 0.001.   
     
     
         10 . The device according to  claim 9 , wherein at least one entity selected from the group consisting of a membrane protein, and an ionophore is associated with the bilayer structure. 
     
     
         11 . The device according to  claim 9 , wherein the bilayer structure comprises at least one liposome tethered to the surface. 
     
     
         12 . The device according to  claim 11 , wherein at least one liposome is tethered to the surface with at least one spacer. 
     
     
         13 . The device according to  claim 12 , wherein the at least one spacer is at least one selected from the group consisting of a polymer, a nucleic acid, DNA, a His-tag, a biotinylated lipid attached to avidin covalently bound to the surface, and hydrophobically modified dextran. 
     
     
         14 . The device according to  claim 9 , wherein the sensor has the capability to measure changes in refractive index in the interval 0-250 nm from the surface. 
     
     
         15 . The device according to  claim 9 , wherein the sensor is selected from the group consisting of a surface plasmon resonance sensor, an ellipsometry sensor, and an optical waveguide laser spectroscopy sensor. 
     
     
         16 . The device according to  claim 9 , wherein the sensor utilizes the phenomenon surface plasmon resonance.