A simple linear sweep voltammetric method for the determination of double-stranded DNA with malachite green

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
W. Sun ◽  
J. You ◽  
X. Hu ◽  
K. Jiao

AbstractIn pH 3.5 Britton—Robinson buffer solution double-stranded (ds) DNA can react with malachite green (MG) to form an interaction complex, which resulted in the decrease of the electrochemical response of MG, MG had a well-defined second-order derivative linear sweep voltammetric peak at −0.73 V (vs. SCE). After the addition of dsDNA into MG solution, the reductive peak current decreased with the positive shift of peak potential, which was the typical characteristic of intercalation. Based on the interaction, an indirect electrochemical determination method for dsDNA was established. The optimum conditions for the reaction were investigated and there were little or no interferences from the commonly coexisting substances. The decrease of peak current was linear with the concentration of dsDNA over the range of 0.8–12.0 µg cm−3 with the linear regression equation as ΔI p″/nA = 91.70 C/(µg cm−3) + 74.55 (n = 10, γ = 0.990). The detection limit was calculated as 0.46 µg cm−3 (3σ). The method had high sensitivity and was further applied to the dsDNA synthetic samples with satisfactory result. The interaction mechanism was discussed with the intercalation of DNA-MG to form a supramolecular complex and the stoichiometry of the supramolecular complex was calculated by electrochemical method with the binding number 3 and the binding constant 2.35 × 1015 (mol dm−3)−3.

2009 ◽  
Vol 74 (12) ◽  
pp. 1467-1476 ◽  
Author(s):  
Weili Zhang ◽  
Xueliang Niu ◽  
Na Zhao ◽  
Wei Sun

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.


2007 ◽  
Vol 72 (11) ◽  
pp. 1085-1094 ◽  
Author(s):  
Wei Sun ◽  
Na Zhao ◽  
Xianlong Yuan ◽  
Kui Jiao

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.


2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.


2014 ◽  
Vol 79 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Xueliang Niu ◽  
Pingping Zhang ◽  
Weili Zhang ◽  
Wei Sun

In this paper, the interaction of cupferron (Cup) and lead (II) complex [Cup-Pb (II)] with chondroitin sulfate (CS) was investigated by linear sweep voltammetric method. In the selected medium of pH 5.5 (acetic acid-hexamine buffer solution), Cup can interact with Pb (II) to form a stable complex of [Cup-Pb(II)], which has a sensitive second order derivative polarographic reductive peak at -0.64V (vs.SCE). After the addition of CS into Cup-Pb (II) complex solution, the reductive peak current decreased without any shift of the peak potential and no new peak appeared, which indicated that an unelectroactive supramolecular complex of CS with [Cup-Pb(II)] was formed. The binding reaction conditions were carefully investigated. Under the optimal conditions, the interaction mechanism was discussed. The decrease of reductive peak current was directly proportional to the CS concentration, thus a new quantitative determination method for CS was established with the linear regression equation as ?Ip?(nA)=36.97 C/mg L-1+12.45 (n=10, ?=0.995). The effects of other substances on the determination were carefully investigated and three synthetic samples were determined with satisfactory results. The binding constant (?s) and the binding number (m) of CS with [Cup-Pb(II)] complex were calculated from the voltammetric data with the results as ?s=1.89?1010 and m?2.5.


2013 ◽  
Vol 9 (2) ◽  
pp. 1900-1910
Author(s):  
WeiLi Zhang ◽  
XueLiang Niu ◽  
Ping Ping Zhang ◽  
Wei Sun

In this paper, the interaction of hyaluronic acid (HA) with crystal violet (CV) was investigated carefully by linear sweep voltammetry on the dropping mercury working electrode (DME). In pH 5.0 Britton-Robinson (B-R) buffer solution, CV has a sensitive, well-defined second order derivative linear sweep voltammetric reductive wave at –0.85 V (vs. SCE). After adding a certain amount of HA into CV solution, the reductive peak current decreased without any shift of reductive peak potential. Based on the difference in the reductive peak current, a new voltammetric method for the detection of HA was established. The reaction conditions and the electrochemical determination were studied and optimized. Under the optimized conditions, the decrease of peak current showed a good linear relationship with the HA concentration in the range from 10.0 to 40.0 mg/L. The linear regression equation was got as ∆ip″(nA)= 84.07 C–527.86  (mg/L) (n=8, γ=0.997) and the detection limit was calculated as 2.65 mg/L (3σ). This new established method was further used to HA determination in the synthetic samples with satisfactory results and good recovery. The stoichiometry of CV-HA complex was calculated and the binding mechanism was also discussed by the electrochemical data.


2014 ◽  
Vol 1040 ◽  
pp. 292-296 ◽  
Author(s):  
Darya A. Vishenkova ◽  
E.I. Korotkova ◽  
Elena V. Dorozhko

In this paper for determination of heparin in pharmaceuticals by constant-current sweep voltammetry on the mercury-film electrode (MFE) we used cationic malachite green (MG) dye which is capable to form a complex with heparin. In the 0.05 M potassium tetraoxalate (KH3C4O8∙ 2H2O) buffer solution with pH 1.65 MG had a well-defined peak of electroreduction at -0.46 V (vs. CSE). During the study of electrochemical properties of heparin in complex with MG in cathodic potential range from 0.0 V to -1.3 V on MFE besides the signal from the dye at E = - 0.46 V the second signal at E = –0.87 V was found. Increasing the concentration of heparin in the solution led to decrease of signal intensity at E = -0.87 V. Optimum conditions for the electrochemical determination of heparin in dosage form with using MG were picked up. Influence of auxiliary components of heparin pharmacological solution on electroreduction of the complex MG-Hep was investigated. Under optimal conditions the decrease of reduction peak currents at E = -0.87 V was proportional to heparin concentration in the range from 3.9 ∙ 10-4mg/ml to 3.9 ∙ 10-3mg/ml.


2015 ◽  
Vol 98 (5) ◽  
pp. 1260-1266 ◽  
Author(s):  
Deng Pan ◽  
Shengzhong Rong ◽  
Guangteng Zhang ◽  
Yannan Zhang ◽  
Qiang Zhou ◽  
...  

Abstract Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of uric acid (UA) at a CdTe quantum dot (QD) modified the glassy carbon electrode (GCE). CdTe QDs, as new semiconductor nanocrystals, can greatly improve the peak current of UA. The anodic peak current of UA was linear with its concentration between 1.0 × 10–6 and 4.0 × 10–4 M in 0.1 M pH 5.0 phosphate buffer solution. The LOD for UA at the CdTe electrode (1.0 × 10–7 M) was superior to that of the GCE. In addition, we also determined the effects of scan rate, pH, and interferences of UA for the voltammetric behavior and detection. The results indicated that modified electrode possessed excellent reproducibility and stability. Finally, a new and efficient electrochemical sensor for detecting UA was developed.


The Analyst ◽  
2016 ◽  
Vol 141 (19) ◽  
pp. 5555-5562 ◽  
Author(s):  
Lili Xiao ◽  
Jiao Yin ◽  
Yingchun Li ◽  
Qunhui Yuan ◽  
Hangjia Shen ◽  
...  

A high sensitivity sensor for detection of hydroquinone and catechol was constructed based on nitrogen and sulfur co-doped activated graphene.


Sign in / Sign up

Export Citation Format

Share Document