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 ...
Read More
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.
Parvin Pourhakkak; Mohammad Ali Karimi; Hossein Tavallali; Pouran Pourhakkak; Mohammad Mazloum Ardakani
Abstract
A new potentiometric sensor based on a β- cyclodextrin modified carbon paste electrode (CPE) was designed for the determination of the captopril drug. The effect of various cyclodextrins (α, β and γ- cyclodextrins) and their percentage, binder agent and ion additive on the potential ...
Read More
A new potentiometric sensor based on a β- cyclodextrin modified carbon paste electrode (CPE) was designed for the determination of the captopril drug. The effect of various cyclodextrins (α, β and γ- cyclodextrins) and their percentage, binder agent and ion additive on the potential response have been investigated and the electrode with the best potential response was found. The linear concentration range for this electrode was 7.0×10-7-1.0×10-1 M with a low detection limit of 2.0 × 10-7 M. The effect of pH and temperature on the Nernstian slope was also investigated and the optimal range was obtained. The selectivity of the captopril CPE to interfering species including Li+, K+, Ni+, Mg2+, Ca2+, Co2+, Cr2+, Cr3+, Zn2+,Mn2+, Fe2+, F-, Cl-, SO42-, C2O42- PO43-, C2O42-, ascorbic acid, uric acid, glucose, D-fructose and sucrose was determined by Separate Solution (SSM) and Matched Potential Method (MPM) methods. Finally, the proposed electrode was tested for measuring captopril in drug formulation, blood serum, and urine samples.
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 × ...
Read More
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.
Afroozeh Arabi; Alireza Mohadesi; Mohammad Ali Karimi; Mehdi Ranjbar
Abstract
In this study, a new Zeolite Al/Na (ZAN) was synthesized and characterized and then a new modified Carbon Paste Electrode with ZAN was made to determine Acetaminophen. Electrochemical studies using Linear Sweep Voltammetry and differential pulse voltammetry were used to determine electrochemical Acetaminophen ...
Read More
In this study, a new Zeolite Al/Na (ZAN) was synthesized and characterized and then a new modified Carbon Paste Electrode with ZAN was made to determine Acetaminophen. Electrochemical studies using Linear Sweep Voltammetry and differential pulse voltammetry were used to determine electrochemical Acetaminophen . In the presence of Acetaminophen , modified electrode with ZAN shows a specific anodic peak at ~ 0.59 volts which is the result of using electrocatalytic oxidation of Acetaminophen . The determination limit of this method to measure Acetaminophen was 5.8 µM, the relative standard deviation for 7 repeated measurements was 1.1 % and linear range of the calibration to measure Acetaminophen was 10 up to 115 µM . for the characterization of ZAN nanostructures we used SEM (Scanning Electron Microscopy), DLS (Dynamic Light Scattering) and FT-IR (Fourier-Transform Infrared spectroscopy).
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 ...
Read More
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.
Jahanbakhsh Raoof; Mohammad Ali Karimi; Leila Asadian-Zarrinabadi; Mohaddeseh Amiri-Aref
Volume 1, Issue 1 , March 2014, , Pages 12-19
Abstract
The electrochemical oxidation and determination of tryptophan (Trp) and glutathione (GSH) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (MWCNT-CPE) using cyclic voltammetry ...
Read More
The electrochemical oxidation and determination of tryptophan (Trp) and glutathione (GSH) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (MWCNT-CPE) using cyclic voltammetry (CV), double step potential chronoamperometry and differential pulse voltammetry (DPV) techniques. The results of differential pulse voltammetry showed two well-resolved anodic peaks for glutathione and tryptophan, which leads to voltammetric determination of each of them. The results shows the electrooxidation peak currents of GSH and Trp is linear in the concentration range of 2×10-6 M-5×10-5 M and 4×10-6 M-6×10-5 M, respectively. The kinetic parameters such as: the chemical reaction rate constant (kh) and transfer coefficient (α) were calculated 2.01×102 cm3 mol-1 s-1 and 0.31, respectively. Also, the apparent diffusion coefficient, Dapp, for GSH was found to be 1.95×10-6 cm2 s-1 in aqueous buffered solution. The proposed method was successfully applied for determination of glutathione and tryptophan in real sample using standard addition method.
