An electrochemical biosensor based on moleculary imprinted polymer for the quantification of creatinine in human urine samples

In this work, we demonstrate the quantification of creatinine (Cre) in human urine by using a molecularly imprinted polymer sensors (MIP). For creatinine binding, a carboxylic polyvinyl chloride (PVC-COOH) layer was functionalized onto screen-printed gold electrodes (Au-SPE). Afterward, a solution of acrylamide and bisacrylamide is polymerized around Au-SPE/PVC-COOH/Cre. For control, a non-imprinted polymer was prepared similarly but without creatinine addition. The MIP morphology and retention properties were monitored, using three instrumental techniques: voltammetry (cyclic voltammetry and differential pulse voltammetry), electrochemical impedance spectroscopy, and UV-Visible spectrophotometry. The MIP didn't recognize analogues, such as urea and glucose. Additionally, the biosensor has proven effective for human urine creatinine determination. Partial Least Squares analysis revealed a good correlation between the biosensor results and the colorimetric method's. Good linearity in the range from 0.1 ng/mL to 1 μg/mL was obtained with a LOD of 0.016 ng/mL, a highly selective recognition ability, simplicity, miniaturisable and cheap.