Hossein Tavalali; Hesamadin Haghdan
Abstract
A novel colorimetric chemosensor for naked-eye detection and determination of Mn2+ and cysteine (Cys) based on indicator displacement assay (IDA) was designed using bromo pyrogallol red (BPR). The indicator exchange occurred between BPR and Cys by the addition of Cys to the Mn(BPR) complex, which is ...
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A novel colorimetric chemosensor for naked-eye detection and determination of Mn2+ and cysteine (Cys) based on indicator displacement assay (IDA) was designed using bromo pyrogallol red (BPR). The indicator exchange occurred between BPR and Cys by the addition of Cys to the Mn(BPR) complex, which is accomplished by an immediate visible color change from purple to magenta, in EtOH/HEPES buffer 10.0 mmol L-1, pH 9.3 (1:4 v/v). The proposed method exhibits a 0.02 μmol L−1 detection limit and good linearity in the range of 0.11–2.87 μmol L−1 for cysteine amino acid. Additionally, the absorption and color change obtained in this chemosensor operate as an “IMPLICATION” logic gate considering Mn2+ and Cys as inputs. Eventually, based on such a fast, reversible, and reproducible signal, a molecular-scale sequential memory unit was designed to display “keypad lock” behavior. The developed chemosensor presented satisfactory repeatability, good precision, and successful application for the selective determination of Cys in human biological fluids. Furthermore, the method's accuracy was evaluated by comparing the results obtained from the proposed method and those from the reference method.
Hossein Tavalali; Abolfath Parhami; Mohammad Ali Karimi; Jamshid Askari
Abstract
In this study, a novel mixed ligand (Dithizone-Co(II)-Alizarin red S: DTZ-Co-ALR-) ensemble is designed and developed ultra-sensitive, and highly selective to UV-Vis absorption and for naked-eye detection of Arginine (Arg), and Glutathione (GSH). The out coming high sensitivity and selectivity for new ...
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In this study, a novel mixed ligand (Dithizone-Co(II)-Alizarin red S: DTZ-Co-ALR-) ensemble is designed and developed ultra-sensitive, and highly selective to UV-Vis absorption and for naked-eye detection of Arginine (Arg), and Glutathione (GSH). The out coming high sensitivity and selectivity for new receptor (DTZ-Co(II)-ALRs-Arg) was attained by adding Glutathione. The indicator is released due to its displacement from the mixed ligand (DTZ-Co-ALRs-Arg) by Glutathione and the change in absorbance may be due to the further complexation of GSH with the additional coordination sites present in the Arg bonded with the mixed ligand (DTZ-Co-ALRs). The label-free DTZ-Co-ALRs receptor provided sensitive and selective detection of L-Arginine, and Glutathione with detection limits of 0.03, and 0.009µmol L-1, respectively. The protocol especially offers high selectivity for the determination of Arg, and GSH among amino acids found in real samples. Moreover, the investigation of the logic behavior of the proposed DTZ-Co-ALRs receptor indicated its capability of functioning as an INHIBIT-type colorimetric chemosensor with the chemical inputs and UV-Vis absorbance signal as the output. This mixed ligand receptor could also behave as a molecular “keypad lock” with the correct sequential addition of Arg and GSH inputs.
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; Mohammad Ali Karimi; Elaheh Sharifi; Zahra Tavallali; Arshida Najafi-Nejad
Abstract
Bromopyrogallol Red (BPR) dye (Dibromopyrogallolsulfonphthalein), was evaluated as a highly selective colorimetric chemosensor for tin and citrate ion. BPR displayed rapid response, high specificity, visual determination and good selectivity toward tin and citrate ion over other competing cations and ...
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Bromopyrogallol Red (BPR) dye (Dibromopyrogallolsulfonphthalein), was evaluated as a highly selective colorimetric chemosensor for tin and citrate ion. BPR displayed rapid response, high specificity, visual determination and good selectivity toward tin and citrate ion over other competing cations and anions in DMSO/H2O (1:1 v/v) media. The sensing mechanism was discussed by UV–Vis, titration, and a comparison study. Over a wide range from 0.4 µmol L-1 to 153.8 µmol L-1 and 0.02 µmol L-1 to 1.08 µmol L-1, a good linear relationship between the absorbance and the concentration of tin and citrate ion was found respectively and the detection limit was estimated to be as low as 0.06 and 0.003 µmol L-1 (S/N = 3) for tin and citrate ion. This proposed chemosensor has also been successfully applied for the determination of citrate in real samples which demonstrates its value of practical applications in food and biological systems.
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.
