title: A rhodamine-based 'turn-on' Al³⁺ ion-selective reporter and the resultant complex as a secondary sensor for F⁻ ion are applicable to living cell staining.
abstract: A newly designed fluorescent aluminum(III) complex (L'-Al; 2) of a structurally characterized non-fluorescent rhodamine Schiff base (L) has been isolated in pure form and characterized using spectroscopic and physico-chemical methods with theoretical density functional theory (DFT) support. On addition of Al(III) ions to a solution of L in HEPES buffer (1 mM, pH 7.4; EtOH-water, 1 : 3 v/v) at 25 °C, the systematic increase in chelation-enhanced fluorescence (CHEF) enables the detection of Al(III) ions as low as 60 nM with high selectivity, unaffected by the presence of competitive ions. Interestingly, the Al(III) complex (L'-Al; 2) is specifically able to detect fluoride ions by quenching the fluorescence in the presence of large amounts of other anions in the HEPES buffer (1 mM, pH 7.4) at 25 °C. On the basis of our experimental and theoretical findings, the addition of Al(3+) ions to a solution of L helps to generate a new fluorescence peak at 590 nm, due to the selective binding of Al(3+) ions with L in a 1 : 1 ratio with a binding constant (K) of 8.13 × 10(4) M(-1). The Schiff base L shows no cytotoxic effect, and it can therefore be employed for determining the intracellular concentration of Al(3+) and F(-) ions by 2 in living cells using fluorescence microscopy.
authors: Department of Chemistry, University of Burdwan, Golapbag, Burdwan 713104, India. pabitracc@yahoo.com.
authors: Buddhadeb
authors: B
authors: Sen
authors: Manjira
authors: M
authors: Mukherjee
authors: Samya
authors: S
authors: Banerjee
authors: Siddhartha
authors: S
authors: Pal
authors: Pabitra
authors: P
authors: Chattopadhyay
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D005459:Fluorides / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D007477:Ions; D008958:Models, Molecular; D012235:Rhodamines / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D013194:Staining and Labeling
chemical_list: D056831:Coordination Complexes; D005456:Fluorescent Dyes; D007477:Ions; D012235:Rhodamines; D012545:Schiff Bases; D000535:Aluminum; D005459:Fluorides