Hossein Tavallali; Abolfath Parhami; Abbas Karimpour; Mohammad Ali Karimi
Abstract
In this study, a new colorimetric sensor based on a couple of Congo Red (CR) and Alizarin Red S (ALRs) was ready for the detection of the carbonate in tracing levels in aqueous media. The linear range of carbonate derived from the results of this simple, selective, and rapid determination, was 1.21 × ...
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In this study, a new colorimetric sensor based on a couple of Congo Red (CR) and Alizarin Red S (ALRs) was ready for the detection of the carbonate in tracing levels in aqueous media. The linear range of carbonate derived from the results of this simple, selective, and rapid determination, was 1.21 × 10-6–9.51 × 10-5 mol L-1 with the detection limit of 1.31 × 10-7 mol L-1. In the examined cases, the concomitant cations, anions, and weak acids ( I-, Br-, F-, Cl-, SCN-, SO32-, S2O32-, S2O82-, OAc-, H2PO4-, HPO42-, NO3-, C2O42-, HCO3-, BrO3-, IO3-, Cit3-), ( K+, Na+, <1.5 × 10-4 mol L-1 ) did not curb the analysis by creating the disturbance of chemical ions. The recoveries shown in the range of 98.6–102.5% indicate the high validity of the method in water samples. Typically, this compound presented was affordable and fast, with a trouble-free operation, which can consider as a good carbonate receiver in running water greenhouses and arable land. In addition, due to the sophisticated modifications made to filter paper strips, this chemical sensor has the potential capacity to be used as a carbonate solid colorimetric indicator.
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.
