• Glassy carbon is a commonly used carbon-based electrode in an analytical laboratory. This is due to its low electrode response and high background current. Thus, modification of this electrode can be completed using various techniques and materials. Ionic liquid (IL) is covalently cross-linked onto glassy carbon surface. Glassy carbon is activated in the sulfuric acid solution by cyclic voltammetry. It generates surface oxygen containing functional groups (for example, OH group), through which ionic liquid is covalently bonded on the surface of glassy carbon