Vivo detection of phospholipase activation

A phospholipid-based near infrared (NIR) molecular beacon comprising a phospholipid moiety with a glycerol backbone, a first fluorophore moiety covalently linked to the glycerol backbone of said phospholipid either directly or via a linker, wherein said first fluorophore moiety is an NIR fluorophore moiety, and a fluorescence quencher moiety covalently linked to said phospholipid glycerol backbone either directly or via a linker, wherein the fluorophore moiety, quencher moiety or both are uncharged when covalently linked at either or both sn-1 or sn-2 fatty acyl positions, wherein a change in NIR fluorescence of said NIR fluorophore is detectable upon cleavage of said phospholipid with a phospholipase.