Carbon nanopowder for sensing of an anticancer drug, raloxifene

Abstract Carbon nanoparticles that have huge electroactive surface area are being exploited in sensing and energy related applications. Self-aggregation of carbon nanopowder limits its applications. In this report, we have demonstrated the solventless dispersion of carbon nanopowder (CNP) into the graphite or carbon paste (CP) matrix for sensing application of an anticancer drug, raloxifene (RLX). Carbon nanopowder was homogeneously distributed into the graphite layers (carbon powder) by hand mixing using agate mortar. The mixture was then blended with trace amounts binder (paraffin) for construction of the electrode, i.e. carbon nanoparticle embedded carbon paste electrode (CNP-CPE). Scanning electron microscopic technique was used to study the surface morphology of electrode materials. Further, the electroactive surface area and the electron transfer properties of the fabricated electrodes were investigated by cyclic voltammetric method. CNP-CP was used for the construction of an electrode (CNP-CPE). RLX showed a reversible (ΔEp1 = 0.065 V) and a quasi-reversible (ΔEp2 = 0.526 V) peak at bare CPE and CNP-CPE. However, the peak current of RLX was observed to be improved by 2-fold at CNP-CPE compared to that at bare CPE. Detailed electrochemical behaviour of RLX was studied by altering pH of the supporting electrolyte and the scan rate. Under the optimized conditions, linearity between the peak current and concentration of RLX was observed in the range of 0.01–40 µM with LOD of 0.55 nM for AdDPSV method and 0.05–40 µM with LOD of 19.5 nM for AdLSSV method. The fabricated electrode, CNP-CPE was successfully used for the determination of RLX in pharmaceutical formulations and RLX fortified biological samples.