Device for Surface Functionalization and Detection

A fluidic device for locally coating an inner surface of a fluidic channel and modifying an inner surface of a fluidic channel with a coating fluid, the fluidic device comprising:

• a first fluidic channel, a second fluidic channel, and a third fluidic channel intersecting at a common junction, wherein the first fluidic channel is connectable to a coating fluid reservoir, wherein the third fluidic channel is connectable to a sample fluid reservoir, and wherein the coating fluid comprises elements that bind to a target analyte in a fluid sample;
• and
• a fluid control means configured for creating a fluidic flow path for a coating fluid at the common junction such that, when coating, a coating fluid propagates from the first fluidic channel to the second fluidic channel via the common junction without propagating into the third fluidic channel;
• wherein the fluid control means comprises a capillary system,
• wherein the capillary system comprises a capillary pump coupled to the second fluidic channel and configured to suction the coating fluid from the first fluidic channel to the second fluidic channel,
• wherein the capillary system is configured to provide a resistivity of the first fluidic channel, a resistivity of the second fluidic channel, a capillary pressure in the capillary pump, and a capillary pressure in the third fluidic channel such that the coating fluid does not flow into the third fluidic channel when propagating from the first fluidic channel to the second fluidic channel, via the common junction, and
• wherein at least part of the first fluidic channel, at least part of the second fluidic channel, or both are dimensioned or shaped such that the resistivity of the first fluidic channel is greater than the resistivity of the second fluidic channel.

A fluidic device for locally coating and modifying an inner surface of a fluidic channel with a coating fluid, the fluidic device comprising:

• a coating fluid reservoir, wherein the coating fluid comprises elements that bind to a target analyte in a fluid sample;
• an outlet vent;
• a first fluidic channel, a second fluidic channel, and a third fluidic channel intersecting at a common junction, wherein the first fluidic channel is connected to the coating fluid reservoir, and wherein the third fluidic channel Is connectable to a sample fluid reservoir;
• and
• a fluid control means configured for creating a fluidic flow path for the coating fluid at the common junction such that, when coating, the coating fluid propagates from the first fluidic channel to the second fluidic channel via the common junction without propagating into the third fluidic channel;
• wherein the fluid control means comprises a capillary system,
• wherein the capillary system comprises a capillary pump coupled to the second fluidic channel and the outlet vent,
• wherein the capillary system is configured to provide a resistivity of the first fluidic channel, a resistivity of the second fluidic channel, a capillary pressure in the capillary pump, and a capillary pressure in the third fluidic channel such that the coating fluid does not flow into the third fluidic channel when propagating from the first fluidic channel to the second fluidic channel, via the common junction, and
• wherein at least part of the first fluidic channel, at least part of the second fluidic channel, or both are shaped such that the resistivity of the first fluidic channel is greater than the resistivity of the second fluidic channel.

A method for partly coating and modifying an inner surface of a fluidic channel with a coating fluid, comprising:

• providing a fluidic device having:
• a first fluidic channel, a second fluidic channel, and a third fluidic channel intersecting at a common junction, wherein the first fluidic channel is connectable to a coating fluid reservoir, wherein the third fluidic channel is connectable to a sample fluid reservoir, and wherein the coating fluid comprises elements that bind to a target analyte in a fluid sample;
• a fluid control means configured for creating a fluidic flow path for the coating fluid at the common junction such that, when coating, the coating fluid propagates from the first fluidic channel to the second fluidic channel via the common junction without propagating into the third fluidic channel;
• wherein the fluid control means comprises a capillary system,
• wherein the capillary system comprises a capillary pump coupled to the second fluidic channel, and
• wherein the capillary system is configured to provide a resistivity of the first fluidic channel, a resistivity of the second fluidic channel, a capillary pressure in the capillary pump, and a capillary pressure in the third fluidic channel such that the coating fluid does not flow into the third fluidic channel when propagating from the first fluidic channel to the second fluidic channel, via the common junction, and
• wherein at least part of the first fluidic channel, at least part of the second fluidic channel, or both are dimensioned or shaped such that the resistivity of the first fluidic channel is greater than the resistivity of the second fluidic channel;
• propagating the coating fluid from the first fluidic channel to the second fluidic channel, via the common junction, thereby coating the common junction and at least a portion of the second fluidic channel;
• and
• while propagating the coating fluid, creating a fluidic flow path at the common junction such that the coating fluid does not propagate into the third fluidic channel.