Electrochemical impedance spectroscopy of the modified fluorine-doped tin oxide glass for determination of creatinine

The design and preparation of a high-performance sensor for determination of creatinine is an interesting research field due to its role in the diagnosis and treatment of kidney diseases. In this work, an enzymeless creatinine sensor was prepared through modification of a fluorine-doped tin oxide (FTO) glass by copper oxide nanoparticles and derivatives of graphite. The graphite derivative was applied on FTO glass using a spin coating method and metal oxide nanoparticles were electrodeposited on the prepared surface using cyclic voltammetry. Electrochemical impedance spectroscopy (EIS) was utilized as the impedimetric method for determinaztion of creatinine. For this purpose, the charge transfer resistance (Rct) values were extracted from Nyquist plot according to a modified Randles equivalent circuit model. The prepared enzymeless sensor indicated a relative good response with a linear concentration range of ۲۰-۵۰ μM. Therefore, this can be used as a sensitive sensor for determination of creatinine in blood and urine samples.