Jump to main content
Jump to site search


An Ampyrone based azo dye as pH-responsive and chemo-reversible colorimetric fluorescent probe for Al3+ in semi-aqueous medium: Implication towards logic gate analysis

Abstract

A novel ampyrone based azo dye, 4-((6-hydroxybenzo[d][1,3]dioxol-5-yl)diazenyl)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (1), has been synthesized by coupling sesamol and 4-amino antipyrine (ampyrone) and was characterized spectroscopically. The interaction of azo dye (1) with different metal ions has been studied using UV-vis and fluorescence spectra. Chemosensor 1 exhibits high selectivity and sensitivity towards Al3+ over other metal ions by fluorescence enhancement in methanol : water (1:1, v/v, at pH = 7.2), which could also be detected directly by the naked eye under visible light. The fluorescence of 1-Al3+ complex was found to be reversible in presence of EDTA. pH-dependent absorption behaviour of chemosensor 1 was also investigated. It was observed that chemosensor 1 could also be used as selective ‘naked-eye’ colorimetric sensor for H+, and displayed a very strong red shift in the absorption band from 492 nm to 540 nm with a notable colour change from yellow to violet-blue. Moreover, the chemosensor 1 showed keto-enol tautomerization in the presence of acidic media and both forms have been confirmed by 1H and 13C NMR spectra. Practical applicability of sensor 1 has been further explored by use of sensing strip analysis which allows rapid detection of Al3+ and H+ ions. NMR and DFT optimized geometries of 1 suggest that the compound is present in the azo form (enol form) in the ground state. In addition, one INHIBIT logic gate was constructed based on multi-responsive properties of 1 induced by Al3+ and EDTA2- which contained two input signals (In1: Al3+, In2: EDTA) and an output signal (O1: Fluorescence intensity at 613 nm. The chemosensor 1 exhibited a high association constant with detection limit of 3.55 x 10-7 M for Al3+ in MeOH-water solution.

Back to tab navigation

Supplementary files

Publication details

The article was received on 30 Oct 2017, accepted on 24 Dec 2017 and first published on 26 Dec 2017


Article type: Paper
DOI: 10.1039/C7NJ04194B
Citation: New J. Chem., 2017, Accepted Manuscript
  •   Request permissions

    An Ampyrone based azo dye as pH-responsive and chemo-reversible colorimetric fluorescent probe for Al3+ in semi-aqueous medium: Implication towards logic gate analysis

    G. Bartwal, K. Aggarwal and J. Khurana, New J. Chem., 2017, Accepted Manuscript , DOI: 10.1039/C7NJ04194B

Search articles by author

Spotlight

Advertisements