Supra-blot: an accurate and reliable assay for detecting target proteins with a synthetic host molecule-enzyme hybrid.

In accordance with the rapid increase in demand for selective and spatial chemical tagging, and accurate detection of proteins of interest, we develop a sensitive protein detection method, termed "Supra-blot" capitalizing on high-affinity host-guest interaction between cucurbit[7]uril (CB[7]) and adamantylammonium (AdA). The method can directly detect chemically tagged proteins without false-positive signals caused by endogenous biomolecules. Not only a single specific protein, but also spatially localized proteins in cells were labeled with AdA, and selectively detected by a host molecule-enzyme hybrid, CB[7]-conjugated horseradish peroxidase (CB[7]-HRP) generating amplified chemiluminescence signals. This study shows the great potential of Supra-blot for accurate and reliable detection of proteins of interest in cells.