The social and economic impact of Chronic Kidney Disease on global health systems is devastating. It is estimated that annual spending on the treatment of Chronic Kidney Patients is in the order of 2 to 3% of annual health budgets. (1) In 2015, considering the United States, medical expenses for individuals with chronic kidney diseases were more than 64 billion dollars (1). Indeed, the early diagnosis of chronic kidney diseases is very important for the implementation of preventive measures that delay or even interrupt the progression to more advanced stages of the disease. In this context, this work aims to develop a disposable electrochemical sensor aimed at detecting creatinine for diagnosing kidney diseases. The flexible disposable lab made carbon sensor has been modified with gold nanoparticles. Morphological and electrochemical characterizations were carried out to better understand the proposed device. From cyclic voltammetry measurements, the proposed sensor showed reduction and oxidation peaks related to gold oxides formed on its surface. When adding creatinine there is a decrease in the electrochemical signal due to the adsorption of the target analyte. Therefore, it was inferred that it was possible to detect creatinine present in the solution from the reduction in the analytical response of the gold-modified electrode. Using the square wave voltammetry technique, in accordance with what was previously presented, when CNN was added to the solution, the Au-CNN interaction caused a reduction in the analytical response, therefore, with the increase in CNN concentration, this reduction increased linearly in the range of 0.5 to 10 µmol L-1 with a limit of detection and quantification, 0.15 and 0.45 µmol L-1, respectively, were calculated. Furthermore, it presented a sensitivity of 0.97 µA mol-1 L with a linear equation of Ipeak (µA) = 0.97 x C(CNN) + 0.23. Furthermore, the proposed sensor was successfully applied to determine creatinine in human serum samples and the recovery results were close to 100%. Therefore, the device modified with gold nanoparticles is an interesting alternative for creatinine detection.References(1) Luyckx V. A. et al. The global burden of kidney disease and the sustainable development goals, Bulletin of the World Health Organization Published online: 20 April 2018.