Device and method for detection of analytes
The present invention provides assays and devices for detection of substances in liquid samples. The assays and devices utilize passive diffusion between a porous material and a porous membrane containing a specific binding pair member to enable detection of the substance of interest.
1. A device for detecting at least one substance of interest in a liquid sample, the device comprising:
(a) a receptacle comprising a porous material for receiving the liquid sample,
wherein the porous material is capable of absorbing and transmitting at least a portion of the liquid sample, and
(b) a porous membrane that comprises a specific binding pair member that is specific for the substance of interest or a substance bound to the substance of interest,
wherein the receptacle and porous membrane are each shaped to permit the porous membrane to be in direct contact with the porous material over at least a portion of the porous membrane that comprises the specific binding pair member such that the porous material is in physical contact with a bottom side of the porous membrane, and wherein the specific binding pair member is in continuous contact with the porous material to allow for continuous diffusion of the liquid sample between the porous material and the specific binding pair member, which is located directly above the porous material to which the liquid sample was applied.
2. The device of claim 1 , further comprising a container containing the receptacle.
3. The device of claim 1 , further comprising a holder for the porous membrane.
4. The device of claim 1 , further comprising a wash solution receiving pad.
5. The device of claim 1 , further comprising a liquid sample application pad.
6. The device of claim 1 , further comprising a filtration pad.
7. The device of claim 1 , wherein the device comprises a container containing a reaction pad comprising the porous material and the porous membrane, the container comprising a holder for the porous membrane, wherein the container causes pressure to be exerted on the porous membrane and/or the porous material such that at least a portion of the porous material is compressed.
8. A device for detecting at least one substance of interest in a liquid sample, the device comprising:
(a) a receptacle comprising a porous material for receiving the liquid sample, wherein the porous material is capable of absorbing and transmitting at least a portion of the liquid sample, and
(b) a porous membrane that comprises a specific binding pair member that is specific for the substance of interest or a substance bound to the substance of interest,
wherein the receptacle and porous membrane are each shaped to permit the porous membrane to be in direct contact with the porous material over at least a portion of the porous membrane that comprises the specific binding pair member such that the porous material is in physical contact with a bottom side of the porous membrane, wherein the specific binding pair member is in continuous contact with the porous material to allow for continuous diffusion of the liquid sample between the porous material and the specific binding pair member, which is located directly above the porous material to which the liquid sample was applied, and wherein the porous membrane and porous material are different elements having a different chemical constitution.
9. The device of claim 8 , wherein the porous membrane and porous material are in physical contact such that liquid sample applied to the porous material diffuses upwards into the porous membrane.
10. The device of claim 8 , wherein the porous material and porous membrane are configured in contact with each other such that the substance of interest does not need to traverse the porous membrane in a unidirectional manner for the device to detect the substance of interest.
11. The device of claim 8 , wherein the porous material and porous membrane are in contact with each other in such a way to permit simple, non-directional diffusion of a liquid between the two to occur.