Electronic detection of interaction and detection of interaction based on the interruption flow

Abstract

Porous members can be positioned so as to partially or fully span channels in microfluidic systems. The porous members can be assembled and/or disassembled in situ. The porous members can be made such that pores are separated by connections including but a single molecule at one location, allowing for a high level of open area in a very small pore size member. The porous member can be made up of colloid particles interconnected with molecular species. These can be used to detect analytes qualitatively and/or quantitatively, or to selectively bind and/or release agents on command for a variety of purposes including first blocking, then opening a channel, concentrating analyte over time followed by release of analyte and detection downstream, etc. Porous members can define valves in multiple-channel systems and, with controlled binding and release of agents at the porous members, these valves can be opened and closed and fluid flow controlled in a multi-channel system. Fluidic systems of the invention can include multiple sensing locations at which different analytes are determined. Systems of the invention provide flexibility for overall microchemical analysis, sequentially, of a variety of agents.

1 . An article comprising: a channel able to contain a flowing fluid; and a porous member at least partially spanning the channel, comprising a colloid particle. 
     
     
         2 . An article as in  claim 1 , wherein the channel has a cross-sectional dimension of less than about 500 microns. 
     
     
         3 . An article as in  claim 1 , wherein the channel has a cross-sectional dimension of less than about 300 microns. 
     
     
         4 . An article as in  claim 1 , wherein the channel has a cross-sectional dimension of less than about 100 microns. 
     
     
         5 . An article as in  claim 1 , wherein the channel has a cross-sectional dimension of less than about 50 microns. 
     
     
         6 . (canceled) 
     
     
         7 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 0.5 micron. 
     
     
         8 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 0.2 micron. 
     
     
         9 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 100 nanometers. 
     
     
         10 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 50 nanometers. 
     
     
         11 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 10 nanometers. 
     
     
         12 . An article as in  claim 1 , wherein the porous member has an average pore size of less than 5 nanometers. 
     
     
         13 . An article as in  claim 1 , wherein the porous member comprises a network of colloid particles interconnected with molecular species. 
     
     
         14 . A method as in  claim 13 , comprising molecular species fastened to colloid particles via affinity tag/recognition entity pairs. 
     
     
         15 . An article as in  claim 13 , comprising at least some colloid particles interconnected with other colloid particles via connections, each connection including, at least one point in the connection, a single molecule. 
     
     
         16 . An article as in  claim 13 , comprising a network of colloid particles interconnected via oligonucleotides. 
     
     
         17 . An article in  claim 1 , the porous member having an open area of at least 70%. 
     
     
         18 . An article in  claim 1 , the porous member having an open area of at least 80%. 
     
     
         19 . An article in  claim 1 , the porous member having an open area of at least 90%. 
     
     
         20 . An article in  claim 1 , the porous member having an open area of at least 95%. 
     
     
         21 . An article in  claim 1 , the porous member having an open area of at least 98%. 
     
     
         22 . An article as in  claim 1 , wherein the channel comprises a groove formed in a surface. 
     
     
         23 . An article as in  claim 1 , wherein the channel is an elongated, enclosed structure having an inlet and an outlet. 
     
     
         24 . An article as in  claim 23 , wherein the channel has a cross-sectional dimension of less than 500 microns and the porous member completely spans the channel and comprises a network of colloid particles interconnected with molecular species and having an open area of at least 70% and an average pore size of less than 0.5 micron. 
     
     
         25 . An article as in  claim 24 , the porous member having an open area of at least 95% and an average pore size of less than 10 nanometers. 
     
     
         26 . An article comprising: a channel able to contain a flowing fluid; and a porous member at least partially spanning the channel, comprising at least two pores separated by a single molecule. 
     
     
         27 - 35 . (canceled) 
     
     
         36 . An article comprising: a channel able to contain a flowing fluid; and a porous member at least partially spanning the channel, having an average pore size of less than 1 micron and an area open to flow of at least 50%. 
     
     
         37 - 48 . (canceled) 
     
     
         49 . An article as in  claim 36 , wherein the channel comprises an elongated, enclosed channel having an inlet and an outlet, and the porous member completely spans the channel such that a fluid flowing through the channel must pass through the porous member. 
     
     
         50 - 52 . (canceled) 
     
     
         53 . A method comprising: passing a fluid through a porous member; allowing a chemical, biological, or biochemical agent within the fluid to bind to a binding partner of the agent immobilized relative to the porous member; determining the binding. 
     
     
         54 - 66 . (canceled) 
     
     
         67 . A method comprising: replacing a first binding partner of a chemical, biological, or biochemical agent immobilized relative to a porous member at least partially spanning a fluid flow channel with a second binding partner without disassembling the porous member relative to the channel. 
     
     
         68 . A method comprising: passing a fluid through a porous medium; allowing a chemical, biological, or biochemical agent within the fluid to bind to a binding partner of the agent immobilized relative to the porous member; and causing the chemical, biological, or biochemical agent to release from the porous member. 
     
     
         69 - 73 . (canceled) 
     
     
         74 . A method comprising: allowing a first chemical, biological, or biochemical agent to become immobilized relative to a first colloid particle and allowing a second chemical, biological, or biochemical agent to become immobilized relative to a second colloid particle; based at least in part on the identity of the first and second agents, directing the first colloid particle to a first fluid channel and directing the second colloid particle to a second channel. 
     
     
         75 . A method comprising: allowing a chemical, biological, or biochemical agent to become immobilized relative to a colloid particle; determining at least one characteristic of the agent; based at least in part on the characteristic, directing the colloid particle to a first fluid channel rather than a second fluid channel, each channel capable of receiving the colloid particle prior to the directing step. 
     
     
         76 . (canceled) 
     
     
         77 . A method comprising: allowing a chemical, biological, or biochemical agent to become immobilized relative to a colloid particle; determining at least one characteristic of the agent at a first detection location; and determining at least one characteristic of the agent at a second detection location. 
     
     
         78 . (canceled) 
     
     
         79 . A method comprising: determining the identity of a chemical, biological, or biochemical agent by determining the flow path of a fluid, initially containing the agent, where the fluid has a plurality of flow path options. 
     
     
         80 . (canceled)