A multi-morphological cu modified electrode for sensitive non-enzymatic creatinine detection

Efficient Cu 2+ -creatinine complexation is essential for the sensitivity of Cu-based non-enzymatic electrochemical creatinine sensors. Herein, a morphological optimization strategy for Cu nanostructures was applied to promote Cu 2+ -creatinine complexation. Accordingly, a screen-printed carbon electrode (SPCE) was pretreated with saturated sodium carbonate to form P-SPCE and subsequently subjected to one-step electrodeposition to fabricate a multi-morphological Cu-modified electrode (Cu/P-SPCE). The resulting multi-morphological Cu architecture enhances creatinine adsorption and facilitates the efficient formation of Cu 2+ -creatinine complexes, leading to improved detection sensitivity. Electrochemical testing revealed that the Cu/P-SPCE sensor achieved a wide linear range from 5 to 400 μM, a sensitivity of 5.01 μA·μM −1 ·cm −2 , and a detection limit of 2.86 μM. It showed promising selectivity for common interferences, such as uric acid and ascorbic acid, and excellent batch-to-batch reproducibility, with a relative standard deviation of 1.40% ( n  = 12). Validation using human urine samples demonstrated good agreement with clinical enzyme assays, with accuracies exceeding 91.50%. These results indicate that morphological optimization of Cu-based electrodes provides an effective strategy for sensitive creatinine detection.