Non-enzymatic free bilirubin electrochemical sensor based on ceria nanocube

Free bilirubin level is a significant indicator for the diagnosis of jaundice related diseases. Herein, ceria nanocubes are synthesized as catalyst for the direct electrochemical sensor of free bilirubin. The sensor is fabricated by simply modifying screen-printed electrodes with ceria nanocubes and carbon blacks. Owing to the catalytical activity of ceria nanocubes and conductivity of carbon blacks, this sensor can detect free bilirubin with high sensitivity and selectivity in a short response time. Under the optimized condition, the current of DPV peak is proportional to the bilirubin concentration up to 100 μM, with a LOD of 0.1 μM in phosphate buffer and 1 μM in human serum sample. The non-enzymatic sensor also shows good reproducibility and stability at room temperature. Moreover, only 5 μL test sample is required, the small sample consumption may facilitate the blood collection procedure. The sensor could be a potential candidate device for the point of care testing on free bilirubin in clinic.