Asymmetric cooperativity in tandem hybridization of enantiomeric metal complex-tethered short fluorescent DNA probes

The complex [Ru(phen)2(dppz)]^2+(phen = 1,10-phenanthroline, dppz = dipyrido[3,2-a:2ʹ,3ʹ-c]phenazine) was attached to the 5ʹ end of a short oligonucleotide to form conjugates, the (delta)-isomer of which showed a high cooperativity during the recognition of the repetitive sequence, while the (lambda)-isomer did not.