A fast and highly selective ECL creatinine sensor for diagnosis of chronic kidney disease†

Monitoring of creatinine in human fluid has attracted considerable attention owing to the potential for diagnosis of chronic kidney disease. However, the detection of creatinine has been difficult owing to its electrochemical and optical inertness. In this approach, a highly selective and sensitive electrochemiluminescence (ECL) strategy based on homogeneous carbon quantum dots (CQDs) for the detection of creatinine was introduced. A copper(II) picrate complex was added at the surface of electrode to improve the selectivity of the sensor significantly by the formation of a Janovsky complex. A multi-pulse amperometric technique was applied as a very fast and reliable method for quantitative determination of creatinine. The calibration curve was acquired with a linear range from 1.0 × 10⁻⁸ to 1 × 10⁻⁵ M with a low detection limit of 8.7 × 10⁻⁹ M. The proposed creatinine sensing platform is experimentally very simple and shows high selectivity with a broad linear range of detection. Furthermore, the presented method can determine creatinine in real samples with excellent recoveries.