earticle

영어

Immobilization of antibodies on carriers in an oriented manner was shown to be critical for achieving high sensitivity in immunoassays. Here we demonstrate the increase in the detection sensitivity of a lateral flow assay for a cardiac marker troponin I (cTnI) by magnetic labels with oriented immobilization of antibodies. For the construction of sensitive magnetic labels, orientated-immobilization of anti-troponin I antibodies on magnetic beads was attempted using protein G. Magnetic beads were first conjugated with protein G followed by immobilization of anti-cTnI monoclonal antibodies. The factors affecting the detection sensitivity in the lateral flow assay system were investigated. The lateral flow assay of cTnI was carried out using the magnetic beads and a Giant magnetoresistive (GMR) sensor at the optimized conditions, and compared with that using conventional random immobilization method. The detection sensitivity in the lateral flow assays using present approach was determined to be about 0.01 ng/mL, showing significantly increased sensitivity compared with conventional immobilization method. This result clearly shows that the magnetic labels with oriented immobilization of antibodies can find wide applications in the lateral flow assays of target analytes.