Unveiling superior creatinine detection: advanced electrochemical biosensor with remarkable sensitivity

The prompt and precise detection of creatinine is essential, as it serves as a critical biomarker for evaluating the severity of kidney disease. This study introduces the development of an innovative non-enzymatic electrochemical biosensor designed for the sensitive detection of creatinine. The biosensor was created by functionalizing carbon nanotubes with anhydrous copper acetate through a simple one-step hydrothermal method. The unique properties of carbon nanotubes provide numerous adsorption sites that promote specific coordination interactions between copper nanoparticles and creatinine, thereby establishing the foundation for the sensor's enhanced sensitivity. The sensor exhibits remarkable specificity, with the creatinine concentration demonstrating a linear response within the range of 0.01 mM to 1 mM, and an exceptional sensitivity of 8617.86 μA mM⁻¹ cm⁻². Notably, superior sensors of this type have been documented, particularly within the narrower concentration range of 0.01 mM to 0.05 mM, indicating that this sensor outperforms others in its class. Furthermore, density functional theory (DFT) calculations, encompassing electron state density, differential charge density, and adsorption energy assessments, corroborate the material's outstanding properties and elucidate the underlying detection mechanism. Furthermore, a range of flexible creatinine sensors was developed utilizing 3D printing and sputtering techniques. These sensors demonstrated exceptional sensing performance, thereby expanding the potential applications of the material and effectively highlighting its intrinsic properties.