title: A three-line lateral flow assay strip for the measurement of C-reactive protein covering a broad physiological concentration range in human sera.
abstract: The lateral flow assay (LFA) strip sensor possesses many advantages as a diagnostic device, including the capabilities of rapid, one-step assay performance, and high throughput production. A major limitation of the sensor, however, is its difficulty in measuring a broad concentration range of target proteins, including C-reactive protein (CRP), due to the "hook effect." In this study, we report the use of a three-line LFA strip sensor, adding an antigen line to the conventional two-line LFA sensor, for detecting CRP within a broad concentration range in human sera. We introduced an antigen line between test and control lines in the LFA sensor. The antigen line was formed by dispensing a CRP antibody solution followed by a CRP solution in nitrocellulose membrane. All other conditions were identical to those applied to the conventional LFA strip sensor. The CRP level in test samples was generated by data processing from the intensities of three lines. The strip sensor measured a linear detection range of CRP concentration from 1 ng/mL to 500 μg/mL within 10 min, with a calculated detection range of 0.69 ng/mL-1.02 mg/mL. Using the developed three-line LFA sensor, 50 clinical samples were measured at a detection range of 0.4-84.7 μg/mL. This novel and easy-to-use CRP sensor can be a useful tool for rapid, sensitive, and cost-effective detection of a broad physiological concentration range of CRP capabilities that are vital for various diagnostic applications.
authors.affiliation: INGIbio Co. Ltd., R&D Center, 206, APRI, 123 Chemdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea.
authors.forename: Young Kyoung
authors.initials: YK
authors.lastname: Oh
authors.affiliation: School of Physics and Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
authors.forename: Hyou-Arm
authors.initials: HA
authors.lastname: Joung
authors.affiliation: Department of Physiology, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea.
authors.forename: Hyung Soo
authors.initials: HS
authors.lastname: Han
authors.affiliation: Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
authors.forename: Ho-Jun
authors.initials: HJ
authors.lastname: Suk
authors.affiliation: INGIbio Co. Ltd., R&D Center, 206, APRI, 123 Chemdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea; School of Physics and Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea. Electronic address: mkim@gist.ac.kr.
authors.forename: Min-Gon
authors.initials: MG
authors.lastname: Kim
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D002097:C-Reactive Protein / Q000032:analysis*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry; D011934:Reagent Strips / Q000032:analysis*
chemical_list: D055910:Antibodies, Immobilized; D011934:Reagent Strips; D006046:Gold; D002097:C-Reactive Protein
keywords: C-reactive protein; Gold nanoparticle; Hook effect; Lateral flow assay; Sandwich immunoassay