Molecularly Imprinted Polymer-Based Electrochemical Sensor for Detection of Urea as a Potential Clinical Biomarker

This study presents a cost-effective and sensitive electrochemical sensing platform for effective detection of urea. A screen-printed electrode (SPE) was modified in situ with molecularly imprinted polymers (MIPs) synthesized using urea as the template molecule. Following electropolymerization, the template was removed using an appropriate desorption agent to generate urea-specific recognition sites within the polymer matrix. Electropolymerization was performed in an aqueous solution in which 3-aminophenylboronic acid (APBA) and pyrrole-3-carboxylic acid served as functional monomers and urea acted as the template molecule. A non-imprinted (NIP) sensor was also prepared under the same electropolymerization conditions, except that urea was omitted from the polymerization solution, in order to provide a control sensor without specific recognition sites for urea. The electrochemical performance of the sensors was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The response difference between MIP and NIP sensors was further evaluated by chronoimpedance measurements. Surface morphology and chemical composition of the modified sensors were characterized by SEM, FTIR, and XPS analyses. The NIP-based sensor exhibited negligible interaction with urea, confirming the specificity of the MIP-modified interface. Subsequently, the analytical performance of the developed sensor was determined through calibration studies. Overall, the results demonstrate that MIP-based sensor provides an efficient approach for urea detection, highlighting its potential as an alternative analytical tool for biomarker-related monitoring applications.