Molecularly-Imprinted Polymer-Based Electrochemical Sensor for Indirect Determination of Memantine: Greenness and Whiteness Assessment

Substantial preference for target analytes was attained by molecularly-imprinted polymers (MIPs). A novel indirect voltammetric technique was developed to provide a useful gate for the analysis of electro-inactive substances through selective interaction with MIP and hence decrease of redox-active probe signal at the electrode’s surface. In this work, a methyldopa-based MIP was fabricated for the selective binding with memantine (MEM), a voltammetry-inactive and widely used drug for Alzheimer’s disease. In-situ electropolymerization of methyldopa monomer was implemented onto a pencil graphite electrode using MEM as a template in phosphate buffer pH 7.0. The monomer-template interaction was evaluated by UV-spectroscopy. The modified surface of the electrode was characterized using scanning electron microscope and X-ray photoelectron spectroscopy. The functionality of the sensor was assessed using cyclic voltammetry and electrochemical impedance analysis. The response was linear over a concentration range of 1.0 × 10 –12 to 1.0 × 10 −10 M with a detection limit down to 1.5 × 10 −13 M. Sensor selectivity was studied using the co-formulated drug, donepezil. The MIP-sensor exhibited high sensitivity and proper selectivity, allowing its applicability for the analysis of MEM in combined formulations and in spiked human plasma samples. The overall process was subjected to a greenness and whiteness assessment, confirming its eco-friendliness and sustainability.