Fang Yan Lu

US Patent:

6485983, Nov 26, 2002

Filed:

May 5, 1999

Appl. No.:

09/305771

Inventors:

Fang Lu - Millbrae CA
Frank N. W. Lu - San Mateo CA
Kai Hua Wang - San Bruno CA

Assignee:

Intec Science, Inc. - Brisbane CA

International Classification:

G01N 33533

US Classification:

436514, 422 56, 422 57, 422 70, 422 8201, 422 8203, 422 98, 422 99, 422110, 4272133, 42721334, 42721335, 436516, 436518, 436530, 436541, 435 3, 435 71, 4352877, 435970, 2041827, 204286, 204288, 204290

Abstract:

System, method, and test strip for solid phase, electrochemical, quantitative analysis of analytes contained in biological fluid samples. Preliminary to analysis, a test sample solution can be applied to a sample collection pad associated with the solid phase test environment of the test strip. The test sample solution and a test kit reagent are thereby initially contacted, under assay conditions, within this solid phase test environment, and caused to migrate along a fluid pathway therein. Irrespective of the assay format (competitive assay, sandwich assay, etc. ), a test kit reagent (e. g. labeled substance) and the analyte of interest (e. g. proteins, hormones or enzymes, small molecules, polysaccharides, antibodies, nucleic acids, drugs, toxins, viruses or virus particles, portions of a cell wall and other compounds which have specific or characteristic markers that permit their identification), either interact with one another to form a complex, or, alternatively, compete with one another for interaction with another test kit reagent, resulting in the concentration of an indicator substance within a delimited area of the solid phase. Thereafter, the delimited area of the test strip is subjected to electrochemical analysis and the results determined by monitoring an electrochemical transition in the form of an indicator, or derivative of the indicator (e. g. indicator species), by potentiostatic or potentiometric quantitative analysis (e. g.

US Patent:

6713308, Mar 30, 2004

Filed:

May 12, 2000

Appl. No.:

09/701922

Inventors:

Fang Lu - Millbrae CA 94030
Frank N. W. Lu - San Mateo CA 94403
Kai Hua Wang - San Bruno CA 94066

International Classification:

G01N 33533

US Classification:

436514, 422 56, 422 57, 422 70, 422 8201, 422 8203, 422 98, 422 99, 422110, 436516, 436518, 436541, 435 3, 435 71, 435 793, 204193, 2042861, 204288, 20440301

Abstract:

The analytical process utilized in the system of this invention comprises three (3) step distinct steps wherein an analyte of interest in a test sample is initially labeled and subsequently isolated within a porous medium of a test device. Once isolated within the medium, the label is displaced from the analyte, or from the complex with the analyte, and converted, under electrolytic condition, to a metallic species which is caused test to deposit upon a working electrode of the test device. This working electrode is part of an electrode array that is positioned coincident with the porous medium, yet maintained physically remote therefrom. This deposit is then stripped from the working electrode, under anodic stripping conditions, and the current generated within the electrode array monitored. The characteristic response curve that is produced thereby can be correlated with the identity and concentration of the analyte(s) with the test sample.

US Patent:

20030236448, Dec 25, 2003

Filed:

Mar 27, 2001

Appl. No.:

09/818000

Inventors:

Fang Lu - Millbrae CA, US
Frank Lu - San Mateo CA, US
Kai Wang - San Bruno CA, US

International Classification:

A61B005/00

US Classification:

600/300000

Abstract:

A system and method for the selective electrochemical analysis of an aqueous test sample for an analyte of interest, with biosensor comprising a working electrode comprising (a) an effective amount of oxidase enzyme specific for the analyte of interest, and (b) a metal catalysts doped carbon composition specific for the catalytic reduction of hydrogen peroxide liberated from enzymatic action of said oxidase upon the analyte of interest. The system and method of this invention effectively perform such selective electrochemical analysis in the presence of common interferents (e.g. acetaminophen, uric and ascorbic acids, catecholamines) at relative low voltages (from about +0.3 to -0.25V), so as to avoid generation of an overlapping signal from such interferents.