ELECTROCHEMICAL BIOSENSOR FOR BRCA1 GENE AND TAMOXIFEN INTERACTION

The electrochemical nanobiosensor was designed for the determination of specific DNA sequences related to breast cancer 1 (BRCA1) gene and interaction between Anticancer Drug Tamoxifen (TAM) and related DNA sequences by using pencil graphite electrode (PGE), bare and multi-walled carbon nanotube (MWCNT) contained screen printed carbon electrodes (SPEs) for the first time. Here, biomolecular interaction between TAM and DNA was investigated differential pulse voltammetry (DPV) based on not only guanine signal but also TAM oxidation response. It was obtained that the guanine signal at about +1.00V obtained from probe DNA or hybrid DNA shows a remerkable increase after the interaction with TAM. Additionally, it was found that TAM interact with guanine bases and TAM signal which is near the guanine oxidation area also increase after the interaction with DNA. Consequently, the prepared biosensor offer suitable platform for the analysis of DNA hybridization and TAM-DNA interaction sensitively

VOLTAMMETRIC ANALYSIS OF TAMOXIFEN RECOVERY AND ITS INTERACTION WITH DNA

The design of biosensors is one of the most important areas of analytical chemistry today, and interest in DNA-based bio (nano) sensors developed to examine applications related to compound-DNA interaction has been increasing in the last two decades. Changing in DNA structure, even for therapeutic purposes, can have serious effects on human health. The detection of any chemical substances in DNA sutructure is very important. In this study, an anticancer drug Tamoxifen (TAM) is used in the treatment of cancer since the early 1970s was identifying the possible DNA interaction during treatment by using differential pulse voltammetry (DPV) based on both TAM and guanine oxidation signals at the disposable pencil graphite electrode (PGE). The effect of TAM on single stranded (ss)-DNA and double stranded (ds)-DNA showed differences, depending on the double helix and single stranded structure. It was found that TAM interacting to ds-DNA more strongly than ss-DNA. Thus, Drug-DNA interaction analysis has been investigated for the first time under optimized conditions with the Tamoxifen which, gave an oxidation peak potential near the guanine oxidation area. These results presented that the developed DNA biosensor could be detected TAM-DNA interaction as a sensitive, rapid and cost effective way. Electrochemical detectionTamoxifen recovery from commercial tablets was also studied

VOLTAMMETRIC AND CHROMATOGRAPHIC DETERMINATION OF NAPROXEN IN DRUG FORMULATION

In this work, the electrochemical oxidation of naproxen (NAP) was studied at an ultra-trace graphite electrode (UTGE). The cyclic voltammetry (CV) technique was used to determine the optimum conditions and the effect of pH on the electrochemical oxidation of NAP. Acetate buffer (pH 4.50) was selected as the support electrolyte due to obtaining the highest electronic signal increase during oxidation of NAP at UTGE. The differential pulse voltammetry (DPV) technique was performed for electrochemical determination of NAP. In the optimum conditions, the limits of detection (LOD) and quantification (LOQ) were determined to be 8.6610-8 M and 2.8810-7 M. In addition, the amount of NAP was determined in drug tablets. The recovery studies of NAP from the drug tablet were completed in order to check the accuracy and precision of the applied voltammetric method. Furthermore, the determination of NAP was performed with the high-performance liquid chromatography (HPLC) method. These two methods were compared in terms of accuracy, precision and recovery studies