Chromogenic and fluorogenic compounds and their use for biological detection

A chromogenic and/or fluorogenic compound having the structure of Formula 1:

• or a salt thereof, wherein:
• each A is an amino acid or a peptide fragment connected to a masked chromophore and/or fluorophore moiety via an enzyme-cleavable amide bond;
• R1 to R8 are each independently selected from hydrogen, halogen, a carboxy, an alkyl, a substituted alkyl, an aryl, a substituted aryl, a heteroaryl group, and a substituted heteroaryl group;
• and
• Z is C(R10R11), wherein R10 and R11 are independently selected from hydrogen, an alkyl, a substituted alkyl, an aryl, a substituted aryl, a heteroaryl group and a substituted heteroaryl group;
• and
• wherein the compound is capable of releasing a detectable chromophore and/or fluorophore in the presence of a target enzyme or analyte that provides for cleavage of the enzyme-cleavable amide bonds.