Abstract
The present study described the construction and the electrochemical futures of a novel inject-printed electrochemical sensor based on spinel ferrite-doped manganese oxide nanoparticles (FMnONPs) for the sensitive differential pulse voltammetric quantification of brimonidine (BRIM) in ophthalmic solutions. At the optimized electroanalytical parameters, calibration graphs were linear within the BRIM concentration range of 24-3512 ng mL-1 and recorded a detection limit value of 8.21 ng mL-1. Cyclic voltammograms recorded at different scan rates indicated an adsorption-reaction mechanism for the electrooxidation of BRIM at the electrode surface with the involvement of two electrons and one proton based on the oxidation of the five-membered ring nitrogen atom as recommended by the molecular orbital calculations. The enhanced performance of the introduced inkjet-printed sensors integrated with FMnONPs encourages their application for monitoring BRIM residues in ophthalmic solutions and biological fluids in the presence of BRIM degradation products and other interferents for diverse quality control applications.