A peroxidase-active aptazyme as an isothermally amplifiable label in an aptazyme-linked oligonucleotide assay for low-picomolar IgE detection.

A peroxidase-active hemin-aptamer was clicked onto an immunoglobulin E (IgE) binding aptamer. The resulting bifunctional aptamer was successfully used in a highly sensitive aptazyme-linked oligonucleotide assay (ALONA) for the detection of IgE. The sensitivity of the assay is enhanced by isothermal amplification of the aptazyme followed by colorimetric detection of the aptazyme's peroxidase activity, which can easily be evaluated even without advanced lab instruments.