Abstract: The present invention provides nanoparticle film and methods of making such films. The nanoparticle film comprises a three dimensional cross-linked array of nanoparticles and linker molecules. The nanoparticle film is coherent, robust and self supporting. The film may be produced by adding linker molecules to a suspension of nanoparticles. The linker molecules form cross-links between the nanoparticles. Prior to completion of the cross-linking reaction the cross-linked nanoparticles are separated from the suspension.

Abstract: The present invention provides an analyte detection device. The device comprises first and second zones, means to allow addition of a probe to the first zone, means to allow addition of a sample suspected to contain an analyte and means to allow passage of the probe from the first zone to the second zone. The first zone contains ligands reactive with the analyte and the second zone includes a membrane the impedance of which is dependent on the presence or absence of the probe and means to measure the impedance of the membrane. It is preferred that the probe includes an ionophore, preferably gramicidin. The present invention also relates to methods of detecting the presence of an analyte.

Abstract: The present invention provides a biosensor for use in detecting the presence of an enzyme or enzymes in a sample. The biosensor comprises a membrane and means for determining the impedance of the membrane. The membrane includes ionophores therein to which are attached linkers. The linkers are cleavable by the enzyme or enzymes to be detected, with the cleavage of the linker causing a change in the ability of ions to pass through the membrane via the ionophores.

Abstract: A device for implant having a biocompatible membrane coating. The membrane comprises a closely packed array of self-assembling amphiphilic molecules and two ionophore components. A receptor molecule reactive with the analyte is provided on one of the ionophore components. The binding of the analyte to the receptor molecule causes a change in the relationship between the ionophore components such that the flow of ion across the membrane is prevented or allowed. The ionophore components are preferably selected from the group consisting of amphotericin B, gramicidin A monomers and combinations thereof, with gramicidin A monomers being particularly preferred. The present invention also provides a membrane including receptors directed against the Fc region of antibodies. These receptors are preferably derived from polyclonal antibodies. These membranes provide a "generic" surface which will bind antibodies in a manner such that the antigen binding regions of the antibody are not hindered.

Abstract: A membrane comprising a closely packed array of self-assembling amphiphilic molecules, and is characterized in that it incorporates a plurality of ion channels, and/or at least a proportion of the self-assembling molecules comprise a receptor molecule conjugated with a supporting entity. The ion channel is selected from the group consisting of peptides capable of forming helices and aggregates thereof, corronands, cryptands, podands and combinations thereof. In the amphiphilic molecules comprising a receptor molecule conjugated with a supporting entity, the receptor molecule has a receptor site and is selected from the group consisting of immunoglobulins, antibodies, antibody fragments, dyes enzymes and lectins. "The supporting entity is selected from the group consisting of a lipid head group, a hydrocarbon chain(s), a cross-linkable molecule and a membrane protein. The supporting entity is attached to the receptor molecule at tan end remote from the receptor site.

Abstract: The present invention provides a biosensor that detects an analyte in a sample by measuring the response of a membrane within which associated ion channels undergo state changes upon interaction between the analyte and the ionic channels. The state change response is detected as result of the change in ionic flow through the membrane.

Abstract: The present invention provides a method of detecting an analyte in a sample the method comprising adding a sample suspected of containing the analyte to a membrane comprising a closely packed array of self-assembling amphiphilic molecules, the membrane including a plurality of ion channels selected from the group consisting of peptides capable of forming helices and aggregates thereof, podands cryptands and coronands, a first receptor moiety reactive with the analyte being attached to the ion channel at an end thereof, the first receptor moiety being such that it normally exists in a first state, but when bound to the analyte exists in a second state, said change of state of the first receptor moiety causing a change in the ability of ions to pass through the ion channel, the first receptor moiety being selected from the group consisting of antigens, peptides, antibodies (e.g.