Efficient Electrochemical Sensing of Tamoxifen with Manganese Tetrachlorophenylporphyrin and Reduced Graphene Oxide Nanocomposite

Abstract

Breast cancer (BC) is one of the leading causes of cancer related deaths in women. Many factors are involved behind the development of BC, for example, abnormal hormonal activity, environmental factors, genetic disorders, lifestyle, and epigenetic regulations. Tamoxifen (TAM), a chemotherapeutic drug, was used in 1960s for the first time for breast cancer treatment. BC is developed by irregular activity of estrogens in body and TAM releases an antiestrogen metabolite i.e., 4-hydroxy tamoxifen to control this sort of tumor. However, TAM detection is necessary for monitoring the treatment of BC as well as to detect the root source of some diseases triggered by excessive amount of TAM in body. In the present study, TAM was electrochemically detected in aqueous media by modifying glassy carbon electrode (GCE) with the nanocomposite of reduced graphene (rGO) and manganese 5,10,15,20-tetrakis (4- chlorophenyl) porphyrin (MnTClPP). Nanocomposite was manufactured by π-π interaction between rGO and MnTClPP in 1:3. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), X-Ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDS) and nuclear magnetic resonance spectroscopy (NMR) were performed for the confirmation of successful fabrication of synthesized materials. Moreover, electrochemical analysis of the various modified electrodes was done via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). A very suitable sensor showing significant anodic peaks of current towards analyte, working at a scan rate of 50mV/s on pH 7, was developed having remarkable values of LoD and LoQ as 0.037nM and 0.124nM, respectively. This sensor was able to perform linearly on a wide range of concentrations of TAM i.e., 1μM- 3mM as well as on large scale of scan rates i.e., 5mV/s – 100mV/s. Various interfering agents i.e., common ions and biomolecules present in body were not able to affect the electrochemical activity of the modified sensor. The sensor also showed admirable reproducibility, stability, sensitivity, and repeatability. The sensor was also capable of performing well in real life samples. This developed sensor also showed extraordinary results for TAM sensing among all the sensors formerly developed for this purpose.