Patent ID: 7781226

Claim:
A method of detecting at least one analyte in a fluid comprising: forming a mixture of one or more first particles with the fluid, wherein each particle comprises a receptor configured to interact with at least a first analyte, and wherein particles that interact with at least a first analyte undergo a detectable spectroscopic change; passing the mixture of first particles and fluid across a porous membrane and a particle-based sensor array disposed in an analyte detection device, wherein the analyte detection device is configured to capture the first particles on the porous membrane allowing at least a second analyte to flow through the membrane and contact a second particle, wherein the analyte detection device comprises: a first sensor comprising the porous membrane configured to capture the first particles, a top member positioned at a spaced distance above the porous membrane such that a first cavity is formed between the top member and the porous membrane, wherein the top member covers at least a portion of the porous membrane, and wherein the top member is substantially transparent to light, and a bottom member positioned below the porous membrane, wherein the bottom member is configured to receive fluid flowing through the porous membrane, and a second sensor in series comprising the particle-based sensor array, wherein the particle-based sensor array is integral with the porous membrane and comprises a plurality of wells fabricated in an ordered array, wherein at least the second particle is positioned within a well and is configured to interact with the second analyte during use to produce a spectroscopic signal; detecting spectroscopic signals produced by the first particles captured on the porous membrane and the second particles in the particle-based sensor array; and determining if one or more analyte is present based on the detected spectroscopic signals.