Enhanced Affinity of Molecularly Imprinted Polypyrrole Film for Creatinine Detection Through Electrochemical Polymerization - Controlled Binding Cavities

Chronic Kidney Disease (CKD) affects millions globally, with diagnosis relying on estimated Glomerular Filtration Rate (eGFR) from creatinine (Cn) measurements, which are costly and time-consuming. Electrochemical sensors based on Molecularly Imprinted Polymers (MIPs) offer a promising alternative for rapid and cost-effective Cn detection. With surface imprinting technique, this study optimized electropolymerized MIP (eMIP) sensors using Ppy monomer printed on SPCE by varying Cn template concentrations (0.2–1.0 M) during polymerization. Characterization via cyclic voltammetry (CV), FTIR, EIS, UV–Vis, and AFM revealed that eMIP 0.4 M demonstrated the most stable binding cavities, crucial for sensor longevity. UV–Vis and AFM analysis further confirmed the superior binding properties of eMIP 0.4 M. The optimized sensor achieved low LOD of 0.00004 M, low LOQ of 0.000133 M, and a linear range detection range of 0.00001–1.0 M for Cn. It exhibited excellent reproducibility and repeatability, with RSD below 13%. The sensor also demonstrated excellent specificity toward creatinine over common interferents and maintained over 83% of its initial signal after three days, confirming its reliability and short-term operational stability for selective creatinine detection. This eMIP sensor platform holds significant potential for point-of-care CKD diagnosis, particularly in resource-constrained environments, where access to traditional testing is limited.