Polarographic determination of DNA based on its interaction with the phenanthroline-zinc(II) complex

By using the linear sweep voltammetric technique, a phenanthroline (Phen) and zinc(II) (Phen-Zn(II)) complex was used as the electrochemical probe for the determination of double-stranded (ds) DNA. In pH 9.0 Britton- -Robinson (B-R) buffer solution, Phen can interact with Zn(II) to form a stable electroactive [Phen-Zn(II)] complex, which had a sensitive second order derivative polarographic reductive peak at -1.300 V (vs. SCE). After the addition of dsDNA into a solution of Phen-Zn(II) complex, the reduction peak current decreased with a negative shift of the reduction peak potential and without the appearance of new peaks. The results showed that a new supramolecular complex was formed via interaction of the Phen-Zn(II) complex with dsDNA. The conditions of interaction and the electrochemical detection were carefully investigated. Under the optimum conditions, the decrease in the reduction peak current was directly proportional to the dsDNA concentration in the range of 0.4-18.0 mg L-1 with the linear regression equation: ?Ip?/nA = 349.48 + + 84.647(c/mg L-1) (n = 13, ? = 0.991) and a determination limit of 0.20 mg L-1 (3?). The relative standard deviation (RSD) for 10 parallel determinations of 10.0 mg L-1 dsDNA was found to be 2.03 %. The method was successfully applied to the detection of synthetic samples with satisfactory results.

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Electrochemical Determination of Metronidazole in Tablet Samples Using Carbon Paste Electrode

Journal of Analytical Methods in Chemistry ◽

10.1155/2016/3612943 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 11

Author(s):

Yosef Nikodimos ◽

Meareg Amare

Keyword(s):

Correlation Coefficient ◽

Carbon Paste Electrode ◽

Reduction Peak ◽

Carbon Paste ◽

Peak Potential ◽

Peak Current ◽

Potential Shift ◽

Scan Rate ◽

Paste Electrode

Cyclic voltammetric investigation of metronidazole at carbon paste electrode revealed an irreversible reduction peak centered at about −0.4 V. Observed peak potential shift with pH in the range 2.0 to 8.5 indicated the involvement of protons during the reduction of metronidazole, whereas the peak potential shift with scan rate in the range 10–250 mV/s confirmed the irreversibility of the reduction reaction. A better correlation coefficient for the dependence of peak current on the scan rate than on the square root of scan rate indicated an adsorption controlled kinetics. Under the optimized method and solution parameters, an excellent linearity between the reductive peak current and the concentration of metronidazole was observed in the concentration range 1.0 × 10−6to 5.0 × 10−4 M with a correlation coefficient, method detection limit (based ons=3σ), and limit of quantification of 0.999, 2.97 × 10−7 M and 9.91 × 10−7 M, respectively. Good recovery results for spiked metronidazole in tablet samples and selective determination of metronidazole in tablet formulations in the presence of selected potential interferents such as rabeprazole, omeprazole, and tinidazole confirmed the potential applicability of the developed method for the determination of metronidazole in real samples like pharmaceutical tablets.

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Voltammetric study of the interaction between oxacillin sodium and cysteine in the presence and absence of Mn(II)ions in neutral buffer solution

Journal of the Serbian Chemical Society ◽

10.2298/jsc0710003b ◽

2007 ◽

Vol 72 (10) ◽

pp. 1003-1013 ◽

Cited By ~ 6

Author(s):

Ender Biçer ◽

Emine Coşkun

Keyword(s):

Square Wave Voltammetry ◽

Catalytic Reduction ◽

Mercury Electrode ◽

Reduction Peak ◽

Peak Potential ◽

Buffer Solution ◽

Voltammetric Study ◽

Wave Voltammetry ◽

Two Peaks ◽

Reduction Peak Potential

In this study, the voltammetric behaviour of the interaction of oxacillin sodium (OXA) and OXA-cysteine (RSH) was studied by square-wave voltammetry, cyclic voltammetry in Britton-Robinson (B-R) buffer (pH 7.0). OXA gave two peaks at -0.248 and -1.224 V. For the interaction, the peak of mercurous cysteine thiolate (Hg2(SR)2) was selected. It was found that the peak currents corresponding to Hg2(SR)2 significantly decreased, while the peak potential shifted to more positive potentials upon the addition of OXA. The observed phenomena are due to the interaction of OXA with RSH on the surface of the mercury electrode. When OXA was added to the electrochemical cell along with Mn(II), new peaks at -0.146 and -0.608 V were observed. These peaks were due to the catalytic activity of OXA on the reduction of Mn(II) and could be attributed to the formation of Mn(II) complexes with different metal/ligand ratios. On the other hand, in the presence of RSH, the peak at -0.608 V vanished and a reduction peak was observed at -0.662 V. The catalytic reduction peak potential of Mn(II) at -0.662 V indicated that RSH slightly prevented the catalysis process of OXA due to their mutual interaction. .

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Sensitive voltammetric detection of yeast RNA based on its interaction with Victoria Blue B

Journal of the Serbian Chemical Society ◽

10.2298/jsc0912467z ◽

2009 ◽

Vol 74 (12) ◽

pp. 1467-1476 ◽

Cited By ~ 1

Author(s):

Weili Zhang ◽

Xueliang Niu ◽

Na Zhao ◽

Wei Sun

Keyword(s):

Interaction Mechanism ◽

Linear Sweep Voltammetry ◽

Reduction Peak ◽

Linear Sweep ◽

Buffer Solution ◽

Peak Current ◽

Voltammetric Detection ◽

Voltammetric Studies ◽

Rna Complex

Voltammetric studies of the interaction of yeast RNA (y-RNA) with Victoria Blue B (VBB) are described in this paper. Furthermore, a linear sweep voltammetric method for the detection of y-RNA was established. The reaction conditions, such as acidity and amount of buffer solution, the concentration of VBB, the reaction time and temperature, etc., were carefully investigated by second order derivative linear sweep voltammetry. Under the optimal conditions, the reduction peak current of VBB at -0.75V decreased greatly after the addition of y-RNA to the solution without any shift of the reduction peak potential. Based on the decrease of the peak current, a new quantitative method for the determination of y-RNA was developed. The effects of co-existing substances on the determination were carefully investigated and three synthetic samples were determined with satisfactory results. The stoichiometry of the VBB-y-RNA complex was calculated by linear sweep voltammetry and the interaction mechanism is discussed.

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Study on the interaction of bovine serum albumin with acid cyanine 5R and its application in analysis

Biochemistry and Cell Biology ◽

10.1139/o05-051 ◽

2006 ◽

Vol 84 (1) ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Fei Lu ◽

Jing-Hao Pan ◽

Yun Liu ◽

Hongfen Zhang ◽

Yujing Guo ◽

...

Keyword(s):

Bovine Serum Albumin ◽

Serum Albumin ◽

Binding Constant ◽

Bovine Serum ◽

Peak Potential ◽

Buffer Solution ◽

Solution Ph ◽

Peak Current ◽

Binding Ratio ◽

Relative Standard

A supramolecular complex of bovine serum albumin (BSA) with acid cyanine 5R (AC 5R, C.I. acid blue 113, C.I.: 26360) has been shown to form in Tris–HCl buffer solution (pH 7.42) by linear sweep voltammetry (LSV), fluorimetry, and spectrophotometry. The binding ratio and binding constant of BSA with AC 5R have been detected by LSV and fluorimetry. The binding mechanism is also preliminarily discussed. In Tris–HCl buffer solution (pH 7.42), AC 5R can easily be reduced on the mercury electrode, and it has a well-defined LSV peak current (Ip) and peak potential (Ep) at –0.65 V (vs. SCE). In the presence of BSA, the Ipof AC 5R decreases, and the peak potential (Ep) shifts to a more positive potential. The decrease of the second-order derivative of reductive peak current (ΔIp") of AC 5R is proportional to the logarithm of BSA concentration in the range of 1.54 × 10–8mol·L–1– 1.54 × 10–5mol·L–1(r = 0.9931 – 0.9977). The limit of detection of BSA is 9.0 × 10–9mol·L–1. The relative standard deviation is 1.83% (n = 10), and the standard recovery is 97.5%–104.8%. This method can be used to determine BSA concentration on the basis of the interaction of BSA with AC 5R.Key words: bovine serum albumin (BSA), acid cyanine 5R (AC 5R), supramolecule, binding ratio, binding constant, fluorimetry, spectrophotometry, electroanalytical method.

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Linear sweep polarographic determination of nucleic acids using acridine orange as a bioprobe

Journal of the Serbian Chemical Society ◽

10.2298/jsc0711085s ◽

2007 ◽

Vol 72 (11) ◽

pp. 1085-1094 ◽

Cited By ~ 2

Author(s):

Wei Sun ◽

Na Zhao ◽

Xianlong Yuan ◽

Kui Jiao

Keyword(s):

Aqueous Solution ◽

Acridine Orange ◽

Electrochemical Method ◽

Electrochemical Determination ◽

Determination Method ◽

Linear Regression Equation ◽

Peak Potential ◽

Linear Sweep ◽

Buffer Solution

The interaction of acridine orange (AO) with double-stranded (ds) DNA in aqueous solution was investigated by linear sweep polarography (LSP) on a dropping mercury working electrode (DME). In pH 2.5 Britton-Robinson (B-R) buffer solution, AO had a sensitive linear sweep polarographic reductive peak at -0.89 V (vs. SCE), which could be greatly inhibited by the addition of dsDNA, with a positive shift of the peak potential. Based on the decrease of the reductive peak current, a new quantitative electrochemical determination method for dsDNA was developed with a linear range of 2.0?20.0 mg l-1 and the linear regression equation: ?Ip" (nA) = 111.90 C (mg l-1)+125.32 (n = 9, ? = 0.997). The influences of commonly co-existing substances, such as metal ions, amino acid, etc., on the determination were also investigated. The method is sensitive, rapid and simple with good selectivity. The new proposed method was further applied to the detection of RNA and three synthetic samples containing dsDNA with satisfactory results. The binding number and the equilibrium constant between dsDNA and AO were calculated by an electrochemical method.

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Sensitive quantification of trace zinc in water samples by adsorptive stripping voltammetry

Water Science & Technology ◽

10.2166/wst.2013.704 ◽

2013 ◽

Vol 69 (2) ◽

pp. 438-442 ◽

Cited By ~ 1

Author(s):

Shahryar Abbasi ◽

Abbas Farmany ◽

Mahmoud Roushani ◽

Seyede Shima Mortazavi

Keyword(s):

Water Samples ◽

Mineral Water ◽

Stripping Voltammetry ◽

Adsorptive Stripping Voltammetry ◽

Complexing Agent ◽

Peak Current ◽

Relative Standard ◽

Preconcentration Time ◽

Influence Of Ph

A simple and sensitive adsorptive stripping voltammetry method was developed for determination of Zn using N-nitrozo-N-phenylhydroxylamine (cupferron) as a selective complexing agent. This complex absorbed on the hanging mercury drop electrode and created a sensitive peak current. The peak current and concentration of zinc accorded with a linear relationship in the range of 0.85–320 ng mL−1. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The relative standard deviation at a concentration level of 50 ng mL−1 was 1.8%. The method was applied to the determination of zinc in city, river and mineral water samples, with satisfactory results.

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Simultaneous Determination of Ternary Mixture of Carboxin, Chlorpyrifos, and Tebuconazole Residues in Cabbage Samples Using Three Spectrophotometric Methods

Journal of Analytical Methods in Chemistry ◽

10.1155/2020/4912762 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Shilan A. Omer ◽

Nabil A. Fakhre

Keyword(s):

Simultaneous Determination ◽

Ternary Mixture ◽

Solid Phase ◽

Ternary Mixtures ◽

Simultaneous Estimation ◽

Great Success ◽

Determination Limit ◽

Spectrophotometric Methods ◽

Relative Standard

Three simple precise and accurate spectrophotometric methods are developed for simultaneous determination of ternary mixtures of carboxin, chlorpyrifos, and tebuconazole residues in cabbage grown in the experimental field. The first method is a double divisor-ratio spectra derivative that relies on the derivative of ratio spectra and attained through dividing the absorption spectra of the ternary mixture by the sum of standard spectrum of a mixture of two from three components, using methanol as a solvent and measuring CAR at 242 nm, CHL at 236 nm, 276 nm, and 300 nm, and TEB at 226 nm. The second method is a successive derivative of ratio spectra which determined CAR at 256 nm and 258 nm, CHL at 290 nm and 292 nm, and TEB at 226 nm and 228 nm. The third method is a mean centering of ratio spectra where CAR, CHL, and TEB were measured at 306 nm, 280 nm, and 240 nm, respectively. These procedures do not involve any previous separation. The extraction of analytes was carried out by using acetonitrile, and the procedure of purification was fulfilled by dispersive solid-phase extraction with a primary-secondary amine (PSA). The proposed methods showed excellent linearity range for three spectrophotometric methods over the concentration ranges of 1–30 μg/mL, 1–50 μg/mL, and 1–45 μg/mL for carboxin, chlorpyrifos, and tebuconazole, respectively. The analytical characteristics such as detection limit, determination limit, relative standard deviation, and accuracy of the three methods were performed. The limits of detection were in the range of 0.153–0.260 μg/mL for carboxin, 0.137–0.272 μg/mL for chlorpyrifos, and 0.109–0.205 μg/mL for tebuconazole with limits of quantification lower than 0.790, 0.824, and 0.621 μg/mL for CAR, CHL, and TEB, respectively. The recoveries ranged from 87.02% to 94.53% for carboxin, 92.32% to 108.53% for chlorpyrifos, and 87.19% to 98.00% for tebuconazole with relative standard deviations less than 5.91%, 5.99%, and 5.53% in all instances for carboxin, chlorpyrifos, and tebuconazole, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed that there were no significant differences between three different spectrophotometric methods. The suggested methods can be applied with great success to the simultaneous estimation of carboxin, chlorpyrifos, and tebuconazole residues in cabbage samples.

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Online Determination of Anionic Surfactant in Environmental Water

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.1113 ◽

2012 ◽

Vol 610-613 ◽

pp. 1113-1116

Author(s):

Liang Wei ◽

Yi Chun Dai

Keyword(s):

Anionic Surfactant ◽

Sodium Dodecyl ◽

Environmental Water ◽

Buffer Solution ◽

Experimental Conditions ◽

Ethyl Violet ◽

Relative Standard ◽

Potassium Hydrogen ◽

Standard Solution

It was found that ethyl violet can react with sodium dodecyl benzene sulfate (SDBS) to form ion associates in pH 2.2 ~ 2.8 of buffer solution of potassium hydrogen phthalate and hydrochloric acid in the presence of polyvinyl alcohol. Based on this, a method was proposed for online determination of anionic surfactant in environmental waterby. Under the optimum experimental conditions, Beers law was obeyed in the concentration range of 80 µg/L ~ 3500 µg/L of anionic surfactant (SDBS). The relative standard deviation of 2.1% was was obtained by injecting 800 µg/L of sodium dodecyl benzene sulfate standard solution (n=10). The detection limit calculated from three times of the average background noise was 4.39 µg/L. The proposed method had been applied successfully to the determination of anionic surfactant in environmental water and the results showed good agreement with that of the standard method.

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Cloud Point Extraction and Spectrophotometry Determination of Lead in Environment Water Using 5-Br-PADAP

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.830.345 ◽

2013 ◽

Vol 830 ◽

pp. 345-348

Author(s):

Lin Gao ◽

Sheng Jie Chen ◽

Fang Chen ◽

Wen Hong Zhou ◽

Jun Long Yao

Keyword(s):

Cloud Point ◽

Cloud Point Extraction ◽

Detection Method ◽

Low Cost ◽

Calibration Graph ◽

Buffer Solution ◽

Relative Standard ◽

Triton X ◽

Optimized Conditions

A simple, sensitive, green and low cost detection method based on the cloud point extraction (CPE) separation and spectrophotometry was proposed for the determination of lead. In pH=9.0 H3BO3 buffer solution, Pb(II) reacts with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of Triton X-100 yielding a hydrophobic complex, which then is extracted into micro-volume surfactant-rich phase. The calibration graph was linear in the range of 20-400 µg/L (at 560 nm). Under the optimized conditions, the detection limits of 10.94 µg/L and the relative standard deviations(RSD) of 2.0% (n=5) for Lead(II) were found, respectively. The sensitivity and absorbance of this method are at least five times higher when compared with that of usual 5-Br-PADAP spectrophotometry without CPE, and the proposed method has been applied to the determination of Lead in environment water samples with satisfactory results.

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