In the first section of this study, porous silicon was synthesized by chemical etching method then nanoalloys Cu-Pt was loaded on porous silicon and was used for detection glucose. The surface morphology, structure, properties and electrochemical behavior of Cu-Pt/PSi were studied using Energy Dispersive X-ray spectroscopy (EDX), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). Glucose was determined by Cu-Pt/PSi with two linear ranges of 1.0-732.0 and 732.0-5025.0 µmol. and detection limit of 0.5 µmol . Finally, the proposed electrochemical sensor applied for determination of glucose in blood serum. In the second section of this study the PSi powder that prepared by the method of metal-assisted chemical etching. Bismuth nanoparticles were deposited on porous silicon (PSi). Bi/PSi/CNTPE was prepared and used as a new electrode for the determination of thioridazine hydrochloride (TR-HCl). The surface structure and properties and electrochemical behavior of Bi/PSi/CNTPE were studies using TEM, XRD, EDX, FT-IR , EIS and CV. Various parameters influencing the sensitivity and selectivity methods such as, potential and time preconcentration, pH and different parameters of differential pulse voltammetry were optimized. A linear range 0.1-260.0 µmol. was achieved with detection limit 30.0 nmol. . Finally, was proposed electrochemical sensor to measure thioridazine in real samples of plasma and commercial tablets with differential pulse voltammetry technique was used.