A novel sensitive electrochemical DNA biosensor for assaying of anticancer drug leuprolide and its adsorptive stripping voltammetric determination
Ankara University, Faculty of Pharmacy, Department of Analytical Chemistry, 06100 Tandogan, Ankara, Turkey.Talanta (Impact Factor: 3.55). 01/2011; 83(3):780-8. DOI: 10.1016/j.talanta.2010.10.049
The anticancer drug, leuprolide (LPR) bound to double-stranded fish sperm DNA (dsDNA) which was immobilized onto the surface of an anodically activated pencil graphite electrode (PGE), was employed for designing a sensitive biosensor. The interaction of leuprolide (LPR) with double-stranded DNA (dsDNA) immobilized onto pencil graphite electrode (PGE) have been studied by electrochemical methods. The mechanism of the interaction was investigated and confirmed by differential pulse voltammetry using two different interaction methods; at the PGE surface and in the solution phase. The decrease in the guanine oxidation peak current was used as an indicator for the interaction in acetate buffer at pH 4.80. The response was optimized with respect to accumulation time, potential, drug concentration, and reproducibility for both interaction methods. The linear response was obtained in the range of 0.20-6.00 ppm LPR concentration with a detection limit of 0.06 ppm on DNA modified PGE and between 0.20 and 1.00 ppm concentration range with detection limit of 0.04 ppm for interaction in solution phase method. LPR showed an irreversible oxidation behavior at all investigated pH values on a bare PGE. Differential pulse adsorptive stripping (AdSDPV) voltammetric method was developed for the determination of LPR. Under these conditions, the current showed a linear dependence with concentration within a range of 0.005-0.20 ppm with a detection limit of 0.0014 ppm. Each determination method was fully validated and applied for the analysis of LPR in its pharmaceutical dosage form.
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- "e l s e v i e r . c o m / l o c a t e / b i o e l e c h e m antidepressant , antibiotics  and anticancer drugs     includingkinase inhibitor imatinibmesylate , heavy metals   and radical species .Comparing with other methods, the dsDNA-electrochemical biosensor shows greater sensitivity towards detecting small perturbations of the DNA double-helical structure and detection of oxidative damage caused to DNA. "
ABSTRACT: Danusertib is a kinase inhibitor and anti-cancer drug. The evaluation of the interaction between danusertib and dsDNA was investigated in bulk solution and using the dsDNA-electrochemical biosensor. The dsDNA-danusertib interaction occurs in two sequential steps. First, danusertib binds electrostatically todsDNA phosphate backbone through the positively charged piperazine moiety. The second step involved the pyrrolo-pyrazolemoiety and led to small morphological modifications in the dsDNA double helix which were electrochemically characterised through the changes of guanine and adenine residue oxidation peaks and confirmed by electrophoretic and spectrophotometric measurements. The nitrenium cation radical product of danusertib amino group oxidation was electrochemically generated in situ on the dsDNA-electrochemical biosensor surface. The danusertib nitrenium cation radical redox metabolite was covalently attached to the C8 of guanine residues preventing their oxidation. An interaction mechanism of dsDNA-danusertib is proposed and the formation of the danusertib redox nitrenium radical metabolite-guanine adduct explained.
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- "Electrochemical DNA biosensors enable the study of the interaction of DNA immobilized on the electrode surface with analytes in solution. Binding of drugs to DNA and a general DNA damage has been described in literature through the variation of the electrochemical signal of guanine or adenine        . To illustrate, in a recent study the interaction was occurred between DNA and mitomycin-C on electrode surface, and it was observed that the guanine signal was higher with bare electrode than DNA-modified one . "
ABSTRACT: Interaction of an antipsychotic agent, aripiprazole, with calf thymus double stranded deoxyribonucleic acid, ct-dsDNA, was investigated by differential pulse voltammetry (using two methods; interaction on the dsDNA modified electrode surface and in solution phase) and UV–VIS spectrophotometry. The binding constant between dsDNA and aripiprazole, K, about 3 × 105 M−1 was obtained spectrophotometrically in 0.1 M acetate buffer, at pH 4.7. Moreover, the DNA-drug association interaction was confirmed by the differential pulse (DP) voltammetric and spectrophotometric investigations of the systems aripiprazole – polyGuanine (polyG) and aripiprazole – polyAdenine (polyA) in solution phase. The interaction between aripiprazole and damaged ct-dsDNA was also investigated using differential pulse voltammetry.
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ABSTRACT: The human metabolic process is a series of reactions between biomolecules in nature. Vitamin B 6 helps protein metabolism and supports DNA repair against free radical damage. Here we reported on studying the electron transfer between DNA and vitamin B 6 by observing the electro-catalytic behaviors of a ssDNA-modified electrode towards vitamin B 6 and determine the quantitative content of vitamin B 6 using the ssDNA-modified electrode. The electron transfer coefficient β was evaluated to be 0.36(±0.02), the standard rate constant k 0 was estimated to be 3.4(±0.1)×10 -4 cm s -1 and the electron transfer number for the rate-determining step is equal to 1. The diffusion coefficient for vitamin B 6 was found to be 4.2(±0.1)×10 -5 cm 2 s -1 . The peak currents depend linearly on the concentration of vitamin B 6 from 0.10 to 6.00 mM with R= 0.99952 (n=8) and SD=0.07008. The linear regression equation was C (mM) = 0.03245 × Ip (µA) -0.04049 with the detection limit of 0.040(±0.001) mM. The determination for the real tablets yielded a good mean recovery of 99.46% with a relative standard deviation of 5.36%. Thus, the method is expected to find its applications in monitoring the content of vitamin B 6 in medical industry.
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