As summarized above, the R1 group can include a biomolecule or {HEAD ~ a chemical group} enabling {TAIL ~ the amplifier} to be attached to a biomolecule 
enabling
As summarized above , the R1 group can include a biomolecule or { HEAD ~ a chemical group } enabling { TAIL ~ the amplifier } to be attached to a biomolecule
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH