Graphite/SiO2 film electrode modified with hybrid organic-inorganic perovskites: Synthesis, optical, electrochemical properties and application in electrochemical sensing of losartan

Hybrid organic-inorganic semiconductors (HOIS) still remain as research focus due to their exceptional optoelectronics properties, placing them as ideal candidates for use in the field of light emitting diodes and photovoltaics. In the present work, HOIS have been synthesized, characterized as well as adsorbed onto graphite/silica film electrodes (GSiHE), the latter used as simple, low cost, yet sensitive, electrochemical sensors. These composite electrodes have been specifically characterized with electrochemical methods and have been applied in the development of prototype electrochemical drug sensors; a paradigm is provided for simple, efficient, sensitive and relatively specific sensing of an antihypertensive drug, losartan (LOS). The electrochemical behavior of GSiHE film modified with HOIS was examined by cyclic voltammetry, while its morphology, structural and spectroscopic properties were investigated by field emission scanning electron microscopy, X-ray diffraction, porosimetry, optical and luminescence spectroscopies. Under optimized conditions, the modified film electrode demonstrated excellent electrocatalytic activity towards oxidation of LOS in the linear response range for concentrations from 4 x 10(-5) M to 3.2 x 10(-4) M (correlation coefficient 0.989) with the limit of detection computed at 3 x 10(-6) M. The sensor takes advantage of the ability of ions to interact with the HOIS lattice on the GSiHE film; this type of sensor has demonstrated good repeatability, reproducibility and stability and was found to be applicable for use in determining pharmaceutical tablet sample concentrations.