Synthesis of a cationic ruthenium(ii) complex and its non-enzymatic glucose-sensing properties

Abstract

The new cationic ruthenium(II) complex (2) was synthesized via the reaction of N,N′-[1,1′-(pyridine-2,6-diyl)bis(ethan-1-yl-1-ylidene)]bis(2-ethyl-6-methylaniline) and [RuCl₂(p-cymene)]₂, and it was fully characterized using NMR, FT-IR, single-crystal X-ray diffraction, ESI-MS, UV-vis, CV and thermal analysis methods; theoretical computational characterizations and geometric parameters for 2 were also carried out via quantum chemical calculations using the density functional theory (DFT) method. In addition, the synthesized Ru(II) complex (2) was immobilized on fabricated RGO-TiO₂@FTO to evaluate its non-enzymatic biosensing properties, and the sensing properties of the resulting Ru(II)-RGO-TiO₂@FTO electrode were recorded. As a glucose-sensing model, at an applied potential of +0.34 V, the Ru(II)-RGO-TiO₂@FTO electrode presented a moderately good sensitivity of 62.69 μA mM⁻¹ cm⁻¹. Various modifications of Ru(II)-RGO-TiO₂@FTO-type electrodes, such as the metal complex, and material types and ratios, will enable the design of future biosensor devices with improved performance.