Fci-fiberchem, Inc.

Stephen L Coulter

Stanley M Klainer

Geoffrey F Hewitt

Devinder P Saini

Simplicity, sensitivity and versatility of optical sensors based on competitive immunoassays using antibody-antigen reactions are achieved by solid-state, single-step reactions which permit accurate sensitive qualitative and quantitative information to be obtained without human participation. All of the chemistry-biochemistry is an inherent part of the sensor. A direct reaction occurs when the sample (antigen) is brought in contact with the sensor. The sensitivity of the competitive immunoassay optical sensor is controlled and increased by selecting a tag for the antigen or altering the attachment of a tag to an antigen so that the binding of tagged antigen to an antibody is decreased relative to the binding of untagged antigen to the antibody. The user can vary size, molecular weight and geometric configuration of the tagged antigen. This can be accomplished by selecting the proper tag or by attaching the indicator material to the antigen through a spacer or by attaching the tag directly to the antigen and attaching a compound of proper molecular weight and size elsewhere. Pretreatment of the substrate to which the antibody-bound tagged antigen is immobilized to block the surface from unwanted interferences and the use of optical isolation increases sensitivity. If the tag cannot be attached to the antigen, it is attached to the antibody. Attaching the controlled size, molecular weight tag to either the antigen or antibody permits the analysis of species not normally measureable by competitive immunoassay, thus increasing the versatility of the method.

Single-step, solid-state competitive immunoassay

Simplicity, sensitivity and versatility of optical sensors based on competitive immunoassays using antibody-antigen reactions are achieved by solid-state, single-step reactions which permit accurate sensitive qualitative and quantitative information to be obtained without human participation. All of the chemistry-biochemistry is an inherent part of the sensor. A direct reaction occurs when the sample (antigen) is brought in contact with the sensor. The sensitivity of the competitive immunoassay optical sensor is controlled and increased by selecting a tag for the antigen or altering the attachment of a tag to an antigen so that the binding of tagged antigen to an antibody is decreased relative to the binding of untagged antigen to the antibody. The user can vary size, molecular weight and geometric configuration of the tagged antigen. This can be accomplished by selecting the proper tag or by attaching the indicator material to the antigen through a spacer or by attaching the tag directly to the antigen and attaching a compound of proper molecular weight and size elsewhere. Pretreatment of the substrate to which the antibody-bound tagged antigen is immobilized to block the surface from unwanted interferences and the use of optical isolation increases sensitivity. If the tag cannot be attached to the antigen, it is attached to the antibody. Attaching the controlled size, molecular weight tag to either the antigen or antibody permits the analysis of species not normally measureable by competitive immunoassay, thus increasing the versatility of the method. Background from displaced tagged antigen can be reduced, and sensitivity increased, by including an interference modifier in the tagged antigen. A gel layer on the sensor extends the ability to detect gaseous or solid species by maintaining the sensing chemistry in an internal wet environment.

Ultrasensitive single-step, solid-state competitive immunoassay sensor

Waveguide sensors are formed on a chip package which contains at least one source and at least one detector. Simple waveguide elements are mounted on the chip. Waveguide defining elements can also be formed integrally with the chip package so that simple waveguide bodies can be inserted or removed. Various geometries of source, reference detector, and sensing detector can be produced. A liquid waveguide sensor is formed by filling a waveguide channel with a liquid reagent or reagents homogeneously dispersed in sol-gels. Sensing waveguides are made of or contain chemistries or biochemistries or are uncoated. Reference waveguides are made of or contain chemistries, biochemistries or materials which are inert to the analyte (sample) of interest. The chip geometries are such that absorption, fluorescence, and refractive index measurements can be made.

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Henderson, NV, United States of America

Stephen L Coulter