Incorporation of triazole into a quinoline-rhodamine conjugate imparts iron(III) selective complexation permitting detection at nanomolar levels.
Two new rhodamine based probes 1 and 2 for the detection of Fe(3+) were synthesized and their selectivity towards Fe(3+) ions in the presence of other competitive metal ions tested. The probe 1 formed a coloured complex with Fe(3+) as well as Cu(2+) ions and revealed the lack of adequate number of coordination sites for selective complexation with Fe(3+). Incorporation of a triazole unit to the chelating moiety of 1 resulted in the probe 2, that displayed Fe(3+) selective complex formation even in the presence of other competitive metal ions like Li(+), Na(+), K(+), Cu(2+), Mg(2+), Ca(2+), Sr(2+), Cr(3+), Mn(2+), Fe(2+), Co(2+), Ni(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+). The observed limit of detection of Fe(3+) ions (5 × 10(-8) M) confirmed the very high sensitivity of 2. The excellent stability of 2 in physiological pH conditions, non-interference of amino acids, blood serum and bovine serum albumin (BSA) in the detection process, and the remarkable selectivity for Fe(3+) ions permitted the use of 2 in the imaging of live fibroblast cells treated with Fe(3+) ions.
Organic Chemistry Division, CSIR-Central Leather Research Institute, Adyar, Chennai-600 020, India.
Narendra Reddy
NR
Chereddy
Sathiah
S
Thennarasu
Asit Baran
AB
Mandal
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000737:chemistry; D005290:Ferric Compounds / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000633:toxicity; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008856:Microscopy, Fluorescence; D041681:NIH 3T3 Cells; D011804:Quinolines / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014230:Triazoles / Q000737:chemistry*
D056831:Coordination Complexes; D005290:Ferric Compounds; D005456:Fluorescent Dyes; D011804:Quinolines; D012235:Rhodamines; D014230:Triazoles; C037219:quinoline