Electro-oxidation study of promethazine hydrochloride at the surface of modified gold electrode using molecular self assembly of a novel bis-thio Schiff base from ethanol media.

In this study, a new Schiff base of bis-N-(2-mercaptophenyl) salicylaldimine (MPSI) has been immobilized on a bare gold electrode as a novel self assembled monolayer (SAM) sensor for determination of promethazine hydrochloride (PMZ). Cyclic voltammetry and electrochemical impedance spectroscopy are used to study the properties of monolayer of Schiff's base on a gold electrode (MPSI-Au SAM electrode) using the [Fe(CN) 6 ] 3 −/4 − probe. Also, the characterization of the MPSI-Au electrode was performed by scanning electron (SEM) and atomic force microscopy (AFM). The electrochemical behavior of PMZ on the MPSI-Au SAM electrode was studied by several voltammetry methods in phosphate buffer solution as supporting electrolyte. The modified electrode showed good selectivity in the presence of interference of ascorbic and uric acid. A calibration curve was obtained for PMZ in a linear range of 1.0–240.0 μmol L − 1 . The detection limit for promethazine hydrochloride was found to be 24.6 nmol L − 1 . The results indicated that the MPSI-Au SAM electrode could be employed for the determination of promethazine hydrochloride in urine and plasma samples. [ABSTRACT FROM AUTHOR]