In general terms, an immunoassay relies on the detection of disease specific markers, which in most cases are proteins, using antibodies that recognize and bind these markers. To obtain a signal from this interaction, a secondary antibody is applied, which in turn is linked to a reporter molecule, and which recognizes the primary antibody. The reporter molecule can for instance be a fluorescent molecule.

However, the sensitivity of these types of setups is limited since each marker molecule leads only to the attachment of one single reporter molecule. Consequently, if the concentration of marker molecules is low, the resulting fluorescence from the immunoassay is so minimal that it cannot be detected.

A successful treatment of certain diseases is dependent upon early detection and diagnosis. However, if the disease is at an early stage, a typical challenge is that protein markers are only found in low concentrations. For this type of diagnostic purpose, a highly sensitive immunoassay is essential – which is not currently available on the market.

Our protein nanofibrils can capture hundreds of secondary antibodies, which are then bound to one single marker molecule. By doing so, hundreds of reporter molecules are able indicate the presence of one marker molecule, which amplifies the fluorescence signal substantially. Therefore, by including our protein nanofibrils into a standard immunoassay, the sensitivity can be increased at least 100-fold.