A novel sensitive electrochemical DNA biosensor for assaying of anticancer drug leuprolide and its adsorptive stripping voltammetric determination.
ABSTRACT 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.
- [Show abstract] [Hide abstract]
ABSTRACT: A simple and inexpensive methodology was used to develop a novel electrochemical sensor for the determination of Sudan II. The interaction of Sudan II with salmon sperm ds-DNA on the surface of salmon sperm ds-DNA-modified pencil graphite electrode (PGE) and in solution phase was studied, using differential pulse voltammetry. The difference between adenine and guanine signals of the ds-DNA after and before interaction with Sudan II was directly proportional to Sudan II concentration, which used for quantitative inspections. Using PGE, a linear calibration curve (R(2)=0.9958) was observed with 0.5-6.0 μg mL(-1) Sudan II. Furthermore, the LOD of 0.4 μg mL(-1) and linear range between 0.5 and 4.0 μg mL(-1) were achieved in solution phase. In the second part, Sudan II was determined on a pretreated pencil graphite electrode by means of adsorptive stripping differential pulse voltammetry. The peak current was linearly dependent on Sudan II concentration over the range of 0.0015-0.30 μg mL(-1), with a detection limit of 0.00007 μg mL(-1) Sudan II. Both ds-DNA-modified PGE and PPGE were applied to analyze Sudan II in real samples.Talanta 01/2012; 88:244-51. · 3.50 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: An electrochemical DNA biosensor was proposed as a screening device for the rapid analysis of folic acid using a pencil graphite electrode modified with salmon sperm ds-DNA. At first, immobilization of the ds-DNA on pencil graphite electrode was optimized using response surface methodology. Solution pH, DNA concentration, time of DNA deposition and potential of deposition was optimized each at three levels. The optimum combinations for the reaction were pH4.8, DNA concentration of 24μgmL(-1), deposition time of 304s, and deposition potential of 0.60V, by which the adenine signal was recorded as 3.04μA. Secondly the binding of folic acid to DNA immobilized on a pencil graphite electrode was measured through the variation of the electrochemical signal of adenine. Folic acid could be measure in the range of 0.1-10.0μmolL(-1) with a detection limit of 1.06×10(-8)μmolL(-1). The relative standard deviations for ten replicate differential pulse voltammetric measurements of 2.0 and 5.0μmolL(-1) folic acid were 4.6% and 4.3%, respectively. The biosensor was successfully used to measure folic acid in different real samples.Materials science & engineering. C, Materials for biological applications. 04/2013; 33(3):1753-8.