Selective recognition of DNA defects by cyclometalated Ir(iii) complexes

Area of Science:

• Coordination Chemistry
• Supramolecular Chemistry
• Chemical Biology

Background:

• Selective detection of DNA defects is crucial for early diagnosis of tumors and diseases.
• Ruthenium(ii), Rhodium(iii), and hybrid complexes have been explored as DNA defect sensors.
• Developing highly selective luminescent probes remains a key challenge in molecular diagnostics.

Purpose of the Study:

• To synthesize and characterize novel heteroleptic cyclometalated Iridium(iii) complexes.
• To evaluate the selective DNA defect recognition capabilities of these complexes.
• To investigate the structure-selectivity relationship in Iridium(iii)-based DNA probes.

Main Methods:

• Synthesis and characterization of three Iridium(iii) complexes: [Ir(phpy)2(imiphen)]+ (Ir-1), [Ir(phpy)2(furphen)]+ (Ir-2), and [Ir(phpy)2(faqphen)]+ (Ir-3).
• Analytical techniques were employed for complex characterization.
• Evaluation of selective binding to specific DNA defects, including abasic sites and various mismatches.

Main Results:

• Ir-1 selectively recognizes abasic sites opposite T and CA mismatches.
• Ir-2 demonstrates preferential recognition of Ab:G mismatches.
• Ir-3 shows high selectivity for TT mismatches.

Conclusions:

• The synthesized Iridium(iii) complexes exhibit high selectivity for distinct DNA defects.
• Fine-tuning ligand structure and metal center choice are critical for developing selective luminescent DNA probes.
• These findings contribute to the advancement of molecular tools for early disease detection.