ChemInform Abstract: Synthesis and Applications of Rhodamine Derivatives as Fluorescent Probes
ABSTRACT Rhodamine dyes are widely used as fluorescent probes owing to their high absorption coefficient and broad fluorescence in the visible region of electromagnetic spectrum, high fluorescence quantum yield and photostability. A great interest in the development of new synthetic procedures for preparation of Rhodamine derivatives has arisen in recent years because for most applications the probe must be covalently linked to another (bio)molecule or surface. In this critical review the strategies for modification of Rhodamine dyes and a discussion on the variety of applications of these new derivatives as fluorescent probes are given (108 references).
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ABSTRACT: The design and development of fluorescent chemosensors have recently been the focus of consider-able attention for the sensitive and specific detection of environmentally and biologically relevant metalions in aqueous solutions and in living cells. Herein, we report photophysical results for a 1H-pyrrole-2-carboxaldehyde-substituted rhodamine 6G derivative (RCS) that possesses specific binding affinitytoward Al3+and Cu2+at micromolar concentration levels. In an N,N-dimethylformamide (DMF) andwater (v/v = 2/8) medium, the RCS chemosensor exhibits a substantially enhanced absorbance inten-sity at 532 nm and a color change from colorless to pink for Cu2+; it also exhibits significant “off–on”fluorescence at 557 nm, accompanied by a color change from colorless to fluorescent-yellow upon bind-ing to Al3+. The RCS sensor exhibits extremely high fluorescence enhancement upon complexation withAl3+, and it can be used as a “naked eye” sensor. Through fluorescence titration at 557 nm, we confirmedthat RCS exhibits a fluorescence response with a remarkable enhancement in emission intensity resultingfrom the complexation between RCS and Al3+, whereas no emission appeared in the case of competitivemetal ions (Cu2+, Al3+, Li+, Na+, K+, Cs+, Mg2+, Ca2+, Fe2+, Co2+, Ag+, Zn2+, Cd2+, Hg2+and Pb2+) in a DMF andwater (v/v = 2/8) solution. The reversible ring-opening mechanism of the rhodamine spirolactam inducedby Al3+/Cu2+binding and the 1:1 stoichiometric structure between RCS and Al3+were adequately sup-ported by Job-plot evaluation, optical titration and FT-IR analysis. The lowest detection limit for Al3+is3.20 × 106M−1in a DMF and water (v/v = 2/8) solution. Al3+-induced chelation-enhanced fluorescence(CHEF) is associated with spirolactam ring opening of the rhodamine unit. Finally, RCS was successfullyapplied for the bio-imaging of Al3+in living HeLa cells and for fluorescence imaging of a microfluidicsystem.Sensors and Actuators B Chemical 01/2015; 210:173-182. DOI:10.1016/j.snb.2014.12.100 · 3.84 Impact Factor
- Dyes and Pigments 01/2015; 112:73-80. DOI:10.1016/j.dyepig.2014.06.021 · 3.47 Impact Factor
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ABSTRACT: An efficient strategy to immobilize a non-aqueous soluble Hg2+ probe onto mesoporous silica is developed, and this immobilization is subject to several advantages regarding Hg2+ detection, such as improving sensing sensitivity and selectivity, extending application from an organic/aqueous mixture to a pure aqueous medium, and achieving removal of Hg2+ ions while detection. The selected Hg2+ probe, rhodamine B thiohydrazide, can be readily covalently immobilized onto mesoporous silica through a simple amide reaction and subsequently exhibits more than 10 times enhancement of sensitivity for Hg2+ (limits of detection are of 0.81 ppb in immobilized form versus 10 ppb in free form), and an adsorption capacity of 192 mg/g. Brunauer-Emmett-Teller and TEM characterizations demonstrate that the mesoporous structure can be well remained after Hg2+ probe modification and this feature is believed to be responsible for improved Hg2+ sensing properties.Dyes and Pigments 12/2014; 111:52–57. DOI:10.1016/j.dyepig.2014.05.034 · 3.47 Impact Factor