In this project, six electrochemical sensors based on application of various modified electrodes for sensitive and selective determination of some pharmaceutical compounds. First, modified graphite pencil electrode activated with multiwall carbon nanotubes was used to determine dexamethasone. After optimization of several effective parameters, dexamethasone was determined in the range of 1.5×10 -7 -1.0×10 -4 mol L -1 and detection limit of 9.0×10 -8 mol L -1 . In the second work, the modified carbon paste electrodes modified with multiwall carbon nanotubes and p -aminophenol was used to the determination of captopril. This sensor was optimized and used for the determination of captopril in the range of 5.0×10 -8 -1.5×10 -5 mol L -1 and detection limit of 2.0×10 -8 mol L -1 . In our third work, ascorbic acid, epinephrine and uric acid were determined simultaneously, using poly(3,3?–bis[n,n–bis(carboxymethyl)aminomethyl]–o–cresolsulfone phthalein) modified glassy carbon electrode. Under the optimum conditions, these compounds, were determined in the ranges of 1.0×10 -6 -2.2×10 -3 , 2.0×10 -7 -1.0×10 -4 and 2.0×10 -8 -2.0×10 -3 mol L -1 and detection limits of 4.0×10 -7 mol L -1 , 3.0×10 -8 and 9.0×10 -9 mol L -1 , respectively. Multiwall carbon nanotubes decorated with gold nano-particles were used to selective and sensitive determination of tamsolusin. Under the optimum conditions, it was determined in the range of 1.0×10 -7 -1.0×10 -3 mol L -1 with detection limit of 1.0×10 -8 ?mol L -1 . In the next section, the moleculary imprinted polymer with multiwall carbon nanotubes was used to determin prednidosolone in the range of, 1.0×10 -7 -1.0×10 -3 mol L -1 with detection limit of 5.0×10 -8 ?mol L -1 , after optimization. Finally, a gold electrode modified with sol gel containing multiwall carbon nanotubes, coated with nano gold was used to the determin of ciprofloxaicne. Under the optimum conditions, ciprofloxacine was determined in the range of, 5.0×10 -8 -4.0×10 -4 mol L -1 with detection limit of 1.0×10 -8 mol L -1 . Various types of electrochemical methods including differential pulse voltammetry, cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy were employed to these studies. Finally, these electrochemical sensors were used for the selective and sensitive quantitative determination of the targets in real biological samples.
