Devices for Analyzing the Presence and Concentration of Multiple Analytes Using a Diffusion-based Chemical Sensor

Abstract

<heading lvl="0">Abstract of Disclosure< / heading> The present invention provides a microfabricated sensor and a method capable of rapid simultaneous measurement of multiple analytes in a fluid sample. The sensor is inexpensive, disposable and portable, and requires only microliters of sample, a particular advantage with precious fluids such as blood. The sensor utilizes diffusion between layered laminar streams rather than side by side streams. This allows multiple side by side channels for simultaneous detection of multiple analytes. In the sensor, a sample stream and a carrier stream flow in layers, one on top of the other, and one or more reagents are introduced to the bottom of the carrier stream through either a fluid or a solid reagent inlet. The reagent contains reagent particles which, in the presence of the analyte, have a detectable change in a property. The analyte diffuses into the carrier stream where it interacts with reagent particles and is detected by optical, electrochemical or other means.

Description

Cross Reference to Related Applications[0001] This application is a continuation-in-part of co-pending application serial no. 09 / 441,572 filed November 17, 1999, which is a divisional of application serial no. 08 / 938,093 filed September 26, 1997, Patent No. 6007,775, both of which are incorporated herein by reference to the extent not inconsistent herewith.Background of Invention[0002] This invention relates to diffusion based microsensors and methods for analyzing the presence and concentration of multiple analytes in samples containing both these analytes and, optionally, larger particles. The invention is particularly useful for analyzing complex samples, such as blood, to detect the presence of small particles, such as ions or proteins, in a stream containing larger particles, such as cells.[0003] The greater diffusion of small particles relative to larger particles can be used to partially separate the species. Diffusion is a process which can easily be neglected at large scale...

AI Technical Summary

Benefits of technology

[0008] The present invention provides a microfabricated sensor capable of rapid simultaneous measurement of multiple analytes in a fluid sample. Reagents can be loaded into the sensor during fabrication and only the sample fluid needs to be introduced for measurement, making it ideal for use outside of the laboratory. The detection apparatus can be as simple as a human eye, a camera, or a voltmeter, which also supports field use. The sensor is sufficiently simple and inexpensive to manufacture that it is practical for disposable use. Multiple analytes can be simultaneously detected with only microliters of sample, a particular advantage with precious fluids such as blood.

[0010] The present invention provides an apparatus and a method which utilize diffusion between layered laminar streams rather than side by side streams. This allows multiple side by side reagent inlets for simultaneous detection of multiple analytes. Additionally, utilizing diffusional separation, the sensor can tolerate fluid samples also containing larger particles.

Problems solved by technology

None of the foregoing publications describe a channel system capable of analyzing small particles in very small quantities of sample containing larger particles, particularly larger particles capable of affecting the indicator used for the analysis.

No devices or methods provide simultaneous measurement of more than one analyte.

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