A dual responsive colorimetric and fluorescent reversible turn-on chemosensor for iron (Fe3+): Computational and spectroscopic investigations

• Published in: Sensors and actuators. B, Chemical Vol. 245; pp. 395 - 405
• Main Authors: Nayab, Pattan Sirajuddin, Shkir, Mohd
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-06-2017; Elsevier Science Ltd
• Subjects: Absorption; Binding; Chemical sensors; Chemical synthesis; Chemoreceptors; Chemosensor; Colorimetric; Colorimetry; DFT study; Energy gap; Ethylenediaminetetraacetic acids; Ferric ions; Fluorescence; Ions; Iron; Molecular orbitals; Reversible; Ring opening; Spectral sensitivity; Spectrum analysis; Structural analysis; Chemosensor; Reversible; DFT study; Colorimetric
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.01.072

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•Design and development of novel Fe3+ specific sensor.•Dual responsive colorimetric and fluorescent probe.•Reversible chemosensor.•Low LOD and high association constant values.•Applicable for both biological and environmental systems.
Herein, we report a highly selective dual responsive chemosensor for detecting iron ion. The structural characterization of synthesized compounds was investigated on the basis of UV–vis, FTIR, 1NMR, 13NMR and Mass spectral data. The sensitivity and selectivity of RDFB toward Fe3+ among different metal ions was examined by absorption, fluorescence, FTIR and mass spectral studies. Complexing with Fe3+ ion leads to spirolactam ring opening of RDFB and consequently causes a color variation from colorless to red. Fe3+-specific binding to RDFB afford a 53-fold enhancement in fluorescence intensity and strong absorption in the visible range. The 1:1 binding mode was proposed on the basis of absorption, FTIR and MS studies. The HOMO and LUMO energy gap for RDFB and RDFB-Fe3+ complex were found to be 3.782eV and 1.875eV suggesting that the interaction of Fe3+ to RDFB reduces the HOMO-LUMO energy gap of the complex and stabilizes the system. The association constant of newly synthesized compound to the receptor is found to be 1.13×105M−1 which further implying the potential of RDFB to acts as a selective chemosensor for Fe3+ ions. Furthermore the reversibility of complexation of RDFB to Fe3+ was also studied by conducting experiments against EDTA.