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.
Sedigheh Kamran; Hossein Tavallali; Ali Azad
Volume 1, Issue 2 , September 2014, , Pages 78-86
Abstract
Fe3O4 magnetic nanoparticles modified with 1-Octyl-3-methylimidazolium bromide([C8MIM]-Fe3O4) were used for the removal of reactive red 141 (RR141) and reactive yellow 81 (RY81) as model azo dyes from aqueous solution. The mean size and the surface morphology of the nanoparticles were characterized by ...
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Fe3O4 magnetic nanoparticles modified with 1-Octyl-3-methylimidazolium bromide([C8MIM]-Fe3O4) were used for the removal of reactive red 141 (RR141) and reactive yellow 81 (RY81) as model azo dyes from aqueous solution. The mean size and the surface morphology of the nanoparticles were characterized by TEM, XRD and FTIR techniques. Adsorption studies of two dyes were performed under different experimental conditions in batch technique. The adsorption of dyes onto [C8MIM]-Fe3O4 nanoparticles was affected by the initial pH, dye concentration, adsorbent amount, contact time and temperature. Experimental results indicated that [C8MIM]-Fe3O4 nanoparticles removed more than 98%. The maximum adsorption capacity of [C8MIM]-Fe3O4 for the Langmuir model was 71.4 mg g−1 and 62.5 mg g−1 for RR141 and RY81, respectively. The isotherm evaluations revealed that the Langmuir model attained better fits to the equilibrium data than the Freundlich model. Adsorption processes onto [C8MIM]-Fe3O4 nanoparticles were spontaneous exothermic and endothermic for RY81 and RR141, respectively. Dyes were desorbed from nanoparticlesby NaCl solution 0.1 mol L−1 at 80 and 30 °C for RR141 and RY81, respectively.
Hossein Tavallali; Gohar Deilamy-Rad; Hoda Ansari
Volume 1, Issue 2 , September 2014, , Pages 87-96
Abstract
A novel magnetic mixed hemimicell solid phase extraction (MMHSPE) technique for speciation analysis of soluble, ferrous and ferric iron in legumes sample by flame atomic absorption spectrometry analysis (FAAS) was developed. MMHSPE system consisting of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3NPs) ...
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A novel magnetic mixed hemimicell solid phase extraction (MMHSPE) technique for speciation analysis of soluble, ferrous and ferric iron in legumes sample by flame atomic absorption spectrometry analysis (FAAS) was developed. MMHSPE system consisting of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3NPs) modified by sodium dodecylsulfate-1-(2-pyridylazo)-2-naphthol (SDS-PAN) have been successfully synthesized as an extracting agent. The procedure is based on complexation of Fe(II) with PAN that immobilized on the SDS-coated Fe3O4/Al2O3 NPs. Total iron is subjected to a similar extraction procedure after reduction. Then Fe(III) has been calculated by subtracting Fe(ΙI) from the total iron. The new and rapid method of analyses (MMHSPE technique) has been successfully applied for the determination of iron ions in certified reference materials (NCS DC 73349—bush, branches and leaves; and TM-23.2—fortified water) and legumes samples with high efficiency. Under the optimum conditions of parameters, the recoveries of Fe(ΙI) by analyzing the seven spiked some legumes samples were between 96.0% and 103.6% and detection limits of Fe(ΙI) were between 1.7 and 3.1 ng mg−1. The results have been also indicated that Fe3+ concentrations obtained are always higher than the Fe2+ contents in legumes sample and Soy bean snack and Peanut have the maximum content of Fe2+.
