The substrate compound 3 in which the one or more non proteinaceous fluorescent moiety comprises {HEAD ~ a dye} selected from a xanthene dye, a rhodamine dye, a fluorescein dye, a cyanine dye, a phthalocyanine dye, a squaraine dye and {TAIL ~ a bodipy dye} 
selected from
The substrate compound 3 in which the one or more non proteinaceous fluorescent moiety comprises { HEAD ~ a dye } selected from a xanthene dye , a rhodamine dye , a fluorescein dye , a cyanine dye , a phthalocyanine dye , a squaraine dye and { TAIL ~ a bodipy dye }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL