The project Digital Plasmonic Biosensor aims at the development of a optical detection concept that
is suitable for rapid analysis of chemical and biological species present in complex biological fluids
and that provide the ultimate sensitivity at single molecule level. It renders a multidisciplinary
research that brings together synthetic chemists, physicists and molecular biologists in order to carry
out advanced antifouling biointerface architectures, optical signal amplification schemes, and assays.
In particular, polymer brush-based modification of metallic nanostructures with high spatial precision
will be pursued. This project component will enable implementing a new approach to the sensitive
detection of individual target molecules that is not affected by the abundant molecules present on
analyzed liquid sample such as blood plasma or serum. Design of these biointerfaces will allow for
efficient metallic nanostructure-enhanced readout of individual binding events that benefit from the
optical amplification associated with resonant excitation of surface plasmons and an assay design
that converts the specific capture of target molecules to strong optical signal change. The project will
utilize plasmonic amplification of scattered light and non-enzymatic amplification of fluorescence
signal based on plasmonically turning emitters from dark state to bright with contrast far exceeding
conventionally used methods. The strong signal amplification will enable to operate the sensor in the
mode of digital readout of binding events when individual molecules captured at the sensor surface
will be counted. The potential of this method will be explored in the context of liquid biopsy
approach for the low-invasive early diagnosis of lung cancer through the monitoring of the presence
of methylated DNA biomarkers in blood plasma-samples.