Patent ID: 8758727
Filing Date: 2014-06-24
Classification: A61K,A61P

Abstract:
1. A contrast marker for indicating a presence of a target cell in an environment, the contrast marker comprising: a fluorophore; a nanometal particle (NMP); a short spacer and a long spacer, each directly linking said fluorophore to said NMP, wherein said short spacer holds said fluorophore at a quenching distance from said NMP and said long spacer holds said fluorophore at a fluorescence enhancing distance from said NMP; wherein said NMP is coated with a targeting biomolecule configured to engage the target cells; and wherein said short spacer is configured to be cleaved by a molecule characterizing the target cells; whereby, before said short spacer is cleaved, said short spacer controls a distance between said fluorophore and said NMP to be the quenching distance, so that the fluorescence is quenched; and whereby, after said short spacer is cleaved, said long spacer controls the distance between said fluorophore and said NMP to be the fluorescence enhancing distance, so that the fluorescence is enhanced.