Hossein Tavallali; Gohar Deilamy-Rad; Abolfath Parhami; Sajedeh Lohrasbi
Volume 3, Issue 2 , September 2016, , Pages 76-87
Abstract
A new diazo based, Congo-Red-Cu , was developed to act as an ‘Off–On’ reversible fluorescent probe for CN− detection. The changes in solvent composition has been shown greatly effective on selectivity of anion sensing through eliminate of sulfite interference. Increasing the amount ...
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A new diazo based, Congo-Red-Cu , was developed to act as an ‘Off–On’ reversible fluorescent probe for CN− detection. The changes in solvent composition has been shown greatly effective on selectivity of anion sensing through eliminate of sulfite interference. Increasing the amount of ethanol up to 5% (v/v) cause a dramatic development in selectivity of CN−via inhibitory effect on sulfite interferent. The chemosensing behavior of the CR-Cu has been demonstrated through fluorescence, absorption, visual color changes and FT-IR studies. This chemosensor (CR-Cu) has been shown a significant visible color change and displays a remarkable fluorescent switch on in the presence of CN− ions. The ‘in situ’ prepared CN− complexes of CR-Cu shows high “Turn-Off” selectivity toward CO32− over the other anions. The detection limits for CN− were 90 and 20 nM for colorimetric and fluorometric methods respectively, that is far lower than the WHO guideline of 1.9 µM. The complex of CN− with CR-Cu also displayed ability to detect up to 15 nM CO32− among other competing anions through a fast response time of less than 30 s which is much lower than most recently reported chemosensor probes. It has been possible to build an INHIBIT logic gate for two binary inputs viz., CN− and CO32− by monitoring the fluorescence emission band at 446 nm as output. The development of fluorometric an ‘‘Off–On’’ reversible switch for three chemical inputs Cu2+, CN− and CO32− ions and mimics a molecular level keypad lock.
