Performance of MXene Modified Molecularly Imprinted Polymer Based Electrodes Compared to Graphene for Electrochemical Sensing of Bilirubin.

Abstract This study presents a comparative analysis of MXene- and graphene-modified molecularly imprinted polymer (MIP) electrodes used for the electrochemical detection of bilirubin (BR), a crucial biomarker for diagnosing liver disorders, neonatal jaundice, and hemolytic diseases. Graphene and MXene were chosen due to their unique properties that enhance the performance of MIP-based electrochemical sensors. The MXene-modified MIP electrode exhibited higher sensitivity (4.685 μA μM -1 cm -2 ) and a lower limit of detection (LOD, 0.1 μM), which is notably better than that of the graphene-modified electrode (1.25 μA μM -1 cm -2 , LOD: 0.42 μM). Nonetheless, the graphene-modified electrode showed higher stability, with 97% of its response remaining after six weeks, due to the rigid carbon network of graphene, while MXene had a retention level of 95%. Both electrodes exhibit high reproducibility (RSD 0.629% for MXene; 1.27% for graphene-modified electrode) and repeatability (RSD 1.29% for MXene; 2.31% for graphene-modified electrode). Additionally, MXene-modified electrodes are more specific towards BR than graphene-modified electrodes because MXene has surface functionality and efficient charge transfer. Therefore, an MXene-modified electrode is better suited for ultra-high sensitivity and selectivity requirements. On the other hand, long-term stability and robustness are more desirable for a graphene-modified electrode, allowing for more prolonged usage.