Porous Nanostructured Chromium-Doped Tungsten Oxide Electrocatalysts for Flutamide and Nilutamide Detection

In the present study, an electrochemical sensor based on a Cr-doped WO 3 nanostructure was designed and exploited for pharmaceutical drug analysis. Cr-doped WO 3 nanostructures were prepared by treating the W and Cr precursors with hydrothermal condensation. A thorough characterization was conducted for structural and elemental insights using scanning electron microscopy, X-ray powder diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy methods. The optimized electrochemical response was obtained with 1.68 atom % of Cr in the WO 3 lattice. The developed nanoparticles were employed in the electrochemical detection of antiandrogen drugs such as flutamide (FLTM) and nilutamide (NLTM) using cyclic voltammetry and square wave voltammetry techniques. The developed sensor was employed to evaluate the physiochemical and thermodynamical parameters of the voltammetric process by investigating the effect of scan rates and temperatures on the quasi-reversible signals of FLTM and NLTM. The Cr-WO 3 /CPE shows a sensitivity of 24.9 and 49.1 μA μM –1 cm –2 for FLTM and NLTM with detection limits of 4.2 and 3.07 nM, respectively. The sensor was employed to detect the desired drug moiety in the urine samples (real and synthetic) and pharmaceutical drugs; the good recovery values demonstrating the applicability and selectivity of the sensor were supported by excipient interference investigation. Thus, the developed sensor and methods hold potential for future research in identifying additional bioactive molecules in pharmaceutical and clinical trials.