서강대학교

초록 (요약문)

Immunoassay is a sensitive diagnostic method with specificity because antigens and antibodies bind with high affinity. As a conventional diagnosis method, enzyme-linked immunosorbent assay (ELISA) is a sensitive tool that measures antigens by a few nM. However, it is not sufficient to measure at lower concentrations. Recently, many researchers have studied to further increase the sensitivity of immunoassay. To detect antigens with high sensitivity, we developed enzyme-cloud bionanoprobe (ECBNP) immobilizing large amounts of horseradish peroxidase (HRP). The enzyme-cloud bionanoprobe was prepared via immobilization of HRP-streptavidin onto the gold nanoparticles (AuNPs) surface followed by the labeling of biotinylated antibodies. Then, biotinylated copolymers which were linked with aldehyde activated HRP by amine-functionalized polymeric branches were conjugated onto the surface of streptavidin coated AuNPs. By using enzyme-cloud bionanoprobe (ECBNP), thioredoxin-1 (Trx-1) which is a biomarker of breast cancer was detected with high sensitivity. In sandwich ELISA system, Trx-1 could be measured within a linear range of 10 pM to 100 nM. ECBNP based ELISA was approximately 103-fold more sensitive than the original ELISA. From these results, synthesized bionanoprobe is expected to be applicable to the early diagnosis as a highly sensitive detection probe.