US 12,031,983 B2
Method for lateral flow immunoassay
Joseph Irudayaraj, Champaign, IL (US); and Wen Ren, Urbana, IL (US)
Assigned to Purdue Research Foundation, West Lafayette, IN (US)
Filed by Purdue Research Foundation, West Lafayette, IN (US)
Filed on Oct. 15, 2021, as Appl. No. 17/502,320.
Application 17/502,320 is a continuation of application No. 16/563,990, filed on Sep. 9, 2019, abandoned.
Claims priority of provisional application 62/744,934, filed on Oct. 12, 2018.
Prior Publication US 2022/0146522 A1, May 12, 2022
Int. Cl. G01N 33/543 (2006.01); B01L 3/00 (2006.01); G01N 33/52 (2006.01); G01N 33/569 (2006.01); G01N 33/58 (2006.01)
CPC G01N 33/54388 (2021.08) [B01L 3/5023 (2013.01); G01N 33/521 (2013.01); G01N 33/56916 (2013.01); G01N 33/586 (2013.01); G01N 33/587 (2013.01)] 8 Claims
 
1. A method of detecting one or more target analytes in a liquid sample, wherein the method comprises:
a) providing a lateral flow strip, wherein the lateral flow strip comprises a sample pad to receiving a liquid sample, a conjugate pad, a sample capture area having pre-loaded antibodies that are capable of binding a target analyte;
b) preparing a liquid sample comprising a complex that comprises a target analyte, streptavidin, gold nanoparticles (GNPs) probes comprising biotinylated and antibody modified gold nanoparticles (GNPs), and an amine-containing chemical loaded liposomes, wherein said streptavidin serves as a linker between said gold nanoparticles (GNPs) probes and said amine-containing chemical loaded liposomes, wherein said gold nanoparticles (GNPs) probes bind to said target analyte through an antibody, and wherein the amine-containing chemical is branched polyethylenimine, or a salt or derivative thereof;
c) loading said liquid sample solution to the sample pad of the lateral flow strip and let the liquid sample migrate along the lateral flow strip to let the target analyte bind with the pre-loaded antibody on the capture area; and
d) providing a detecting agent comprising gold nanoparticles and a hydrolytic agent and allowing the detecting agent to contact the lateral flow strip one or more times to generate a colorimetric signal that shows the existence of the target analyte, wherein the hydrolytic agent is capable of hydrolysis of said liposomes to release said amine-containing chemical.