Simultaneous analyte determination and reference balancing in reference T-sensor devices

A system for detecting the presence or determining the concentration of analyte particles in a sample stream comprising:

• (a) a device comprising:
• (i) a laminar flow channel;
• (ii) at least three inlet means in fluidic connection with said laminar flow channel for respectively conducting into said laminar flow channel (1) an indicator stream, (2) a sample stream, and (3) a reference stream;
• and
• (iii) detection means positioned relative to said flow channel to measure a value for a detectable property in at least one of said streams;
• and
• (b) means for correlating said measured value with standard values for said detectable property in said system.

A device for detecting the presence or determining the concentration of analyte particles in a sample stream comprising:

• (a) a substrate;
• (b) a plurality of laminar flow channels within said substrate;
• (c) a plurality of indicator stream inlet channels in fluidic connection with each of said laminar flow channels for conducting an indicator stream into each of the laminar flow channels;
• (d) a sample stream inlet channel in fluidic connection with at least one of said laminar flow channels, positioned for conducting a sample stream therein into laminar flow contact with an indicator stream, and
• (e) a single detection means positioned relative to said laminar flow channels so as to detect changes in fluids within all of said laminar flow channels.

A method for making a system for detecting the presence or determining the concentration of analyte particles in a sample stream comprising:

• (a) providing a substrate;
• (b) forming a laminar flow channel in said substrate;
• (c) forming at least three inlet means in fluidic connection with said laminar flow channel in said substrate;
• (d) flowing a reagent stream into an inlet means between two of the other inlet means;
• (e) flowing a sample stream into at least one of the other inlet means adjacent the reagent inlet means;
• and
• (f) detecting the presence or determining the concentration of analyte particles in a diffusion zone between the reagent stream and the adjacent sample stream.

A method for calibrating a device for determining the concentration of analyte particles in a sample stream comprising:

• (a) conducting a plurality of calibration streams, each containing a different known concentration of analyte particles, into one or more laminar flow channels of said device;
• (b) conducting a plurality of indicator streams, each having the same composition and comprising an indicator substance which indicates the presence of said analyte particles by a change in a detectable property when contacted with particles of said analyte, into said laminar flow channel(s), whereby each of said calibration streams is in laminar flow with at least one of said indicator streams;
• (c) conducting a first internal standard stream having a known concentration of analyte particles higher than that of said calibration streams, and a second internal standard stream having a known concentration of analyte particles lower than that of said calibration streams, into laminar flow with at least one of said indicator streams;
• (d) measuring a value of a detectable property in said indicator streams indicative of the concentration of analyte particles in adjacent calibration or internal standard streams;
• and
• (e) plotting the measured values for said calibration streams against the average value for said internal standard streams to obtain a calibration curve for said device.

A method for detecting the presence or determining the concentration of analyte particles in a sample stream, comprising:

• (a) continuously conducting said sample stream into a laminar flow channel;
• (b) continuously conducting an indicator stream, said indicator stream comprising an indicator substance which indicates the presence of said analyte particles by a change in a detectable property when contacted with particles of said analyte, into said laminar flow channel, whereby said sample stream and said indicator stream flow in adjacent laminar flow in said channel;
• (c) continuously conducting a reference stream, comprising a constant concentration of 0 or greater of reference particles into said laminar flow channel, whereby said reference stream flows in a laminar stream adjacent to said indicator stream;
• (d) allowing analyte particles to diffuse into said indicator stream;
• (e) allowing reference particles to diffuse into said indicator stream;
• and
• (f) continuously monitoring the presence or determining the concentration of said analyte and reference particles in said indicator stream.