The composition of claims 1 or 2 wherein, when B is cationic, M is an anion and s is from 1 to about 8; when B is nonionic, B is polyethoxylate, M is zero, s is from 1 to about 8, and the number of condensed ethylene oxide molecules per porphine molecule is from about 8 to about 50; when B is anionic and proximate, M is cationic and s is from 3 to about 8; when B is anionic and remote, M is cation