Multiplexed immunoassay using the stabilized enzymes in mesoporous silica.
Multiplexed immunoassay system was developed using the enzyme-immobilized mesoporous silica in a form of nanoscale enzyme reactors (NERs), which improve the enzyme loading, activity, and stability. Glucose oxidase (GO) and trypsin (TR) were adsorbed into mesoporous silica and further crosslinked for the construction of NERs, and antibody-conjugated NERs were employed for the analysis of target antigens in a sandwich-type magnetic bead-based immunoassay. This approach, called as NER-LISA (NER-linked immunosorbent assay), generated signals out of enzyme reactions that correlated well with the concentration of target antigens. The detection limit of NER-LISA using NER-GO and anti-human IgG was 67pM human IgG, and the sensitivity was 20 times higher than that of the conventional ELISA using anti-human IgG conjugated GO. Antibody-conjugated NER-GO and NER-TR were successfully employed for the simultaneous detection of two target antigens (human IgG and chicken IgG) in a solution by taking advantage of signals at different wavelengths (absorbances at 570nm and 410nm, respectively) from the assays of GO and TR activities, demonstrating the potential of NER-LISA in multiplexed immunoassay. The NER-LISA approach also enabled the successful use of a protease (trypsin), because the NER approach can effectively retain the protease molecules within the mesoporous silica and prevent the digestion of antibodies and enzymes during the whole process of NER-LISA.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
Yunxian
Y
Piao
Dohoon
D
Lee
Jinwoo
J
Lee
Taeghwan
T
Hyeon
Jungbae
J
Kim
Hak-Sung
HS
Kim
D015374:Biosensing Techniques / Q000295:instrumentation*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005949:Glucose Oxidase / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000032:analysis*; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D014357:Trypsin / Q000737:chemistry*
D004800:Enzymes, Immobilized; D007074:Immunoglobulin G; D012822:Silicon Dioxide; D005949:Glucose Oxidase; D014357:Trypsin