The invention provides isolated MMP-2, MMP-9 and MT1-MMP selective substrate polypeptides or functional peptidomimetics. The selective substrate polypeptides contain the following sequences: MMP-2 selective substrate polypeptides contain SEQ ID NOS:1-27, MMP-9 selective substrate polypeptides contain SEQ ID NOS:28-35, and MT1-MMP selective substrate polypeptide contain SEQ ID NOS:36-40. In addition, the invention provides a method of preferentially directing a moiety to a site of MMP-2 activity by administering to a subject an effective amount of an isolated MMP-2 selective substrate polypeptide containing SEQ ID NOS:45-47 linked to a moiety. Also provided is a method of preferentially directing a moiety to a site of MMP-9 activity by administering to a subject an effective amount of an isolated MMP-9 selective substrate polypeptide containing SEQ ID NO:44 linked to a moiety, and preferentially directing a moiety to a site of MT1-MMP activity by administering to a subject an effective amount of an isolated MT1-MMP selective substrate polypeptide containing SEQ ID NOS:36-40 linked to a moiety.