Detection of protein targets with a single binding epitope using DNA-templated photo-crosslinking and strand displacement

DNA-based probes are powerful analytical tools for protein detection and analysis. Target-induced DNA assembly is a widely used strategy to transduce target-ligand binding to detectable signals. However, most of the existing methods based on DNA assembly require two or more binding sites on the target protein. Here we report a novel detection method suitable for protein targets with just a single binding site. This method is based on target-induced probe assembly, DNA-templated photo-crosslinking, and DNA-mediated toehold strand displacement to form a tri-probe complex that is specific for target protein.