title: Chemiluminometric Immunosensor for High-Sensitivity Cardiac Troponin I Employing a Polymerized Enzyme Conjugate as a Tracer.
abstract: To detect high-sensitivity cardiac troponin I (hs-cTnI; <0.01 ng/mL) at points of care, we developed a rapid immunosensor by using horseradish peroxidase polymerized in 20 molecules on average (Poly-HRP) as a tracer conjugated with streptavidin (SA-Poly-HRP). As shown in the conventional system, enhanced sensitivity could be achieved by using a sequential binding scheme for the complex formation to contain the huge molecular tracer. We used a 2-dimensional chromatographic technology to carry out the sequential bindings in cross-flow directions. After the complex formation of antigen-antibody with analyte in a vertical direction, SA-Poly-HRP was horizontally supplied across the membrane strip for additional binding via a biotin-SA linkage. The HRP substrate was subsequently supplied along the same direction to produce a chemiluminometric signal, which was measured by a cooled charge-coupled device. Hs-cTnI analysis was completed in this format within 25 min, and the results showed a high correlation with those of the CentaurXP® reference system (R(2) > 0.99). The detection limit of the rapid immunosensor was 0.003 ± 0.001 ng/mL cTnI, corresponding to a 10-fold improvement compared to results using the plain enzyme tracer. This demonstrated the measurement of hs-cTnI in a much more cost-effective manner compared to the automated versions currently available.
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.|Devices and Materials Laboratory, LG Electronics Advanced Research Institute, Seocho-gu, Seoul 137-724, Korea.
authors.forename: Guei-Sam
authors.initials: GS
authors.lastname: Lim
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Seo
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Paek
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.
authors.forename: Seung-Wan
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Jeon
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.
authors.forename: Dong-Hyung
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Biomedical Laboratory Science, Eulji University, Seongnam, Gyeonggi-do 461-713, Korea.
authors.forename: Il-Hoon
authors.initials: IH
authors.lastname: Cho
authors.affiliation: Department of Bio-Microsystem Technology, Korea University, Sungbuk-gu, Seoul 136-701, Korea.|Department of Biotechnology and Bioinformatics, Korea University, Sejong 339-700, Korea.
authors.forename: Se-Hwan
authors.initials: SH
authors.lastname: Paek
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D019809:Streptavidin / Q000378:metabolism*; D019210:Troponin I / Q000032:analysis* / Q000378:metabolism
chemical_list: D019210:Troponin I; D001710:Biotin; D019809:Streptavidin; D006735:Horseradish Peroxidase