In one most preferred embodiment, {HEAD ~ the dye} is {TAIL ~ N N} 3,3,3,3 tetramnethylbenzindodicarbocyanine, which has the formula: ##STR3## 
In one most preferred embodiment , { HEAD ~ the dye } is { TAIL ~ N N } 3,3,3,3 tetramnethylbenzindodicarbocyanine , which has the formula : # # STR3 # #
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH