An MXene-supported cobalt-MOF nanocomposite-printed electrochemical sensor with high sensitivity for blood creatinine detection in point-of-care settings.

2D MXenes have been used as electrochemical sensor materials, but their output current signal remains weak in point of care (PoC) settings. To address this issue, here we report a novel MXene-supported cobalt-MOF-based nanocomposite, which is used with a carbon black (CB) ink and 3-D printed as the CoMOF-MXene@CB layered electrode structure for the development of a sensor electrode and a PoC chip for electrochemical detection of blood creatinine with an enhanced current range, specificity, and sensitivity. The limit of detection (LOD) and sensitivity of the fabricated sensor were found to be 0.005 μM and 1.1 μA μM cm, which are 44 times lower and 32 times enhanced, respectively, as compared to the existing literature report (LOD 0.22 μM and sensitivity 0.034 μA μM) for creatinine sensing in PoC settings. The sensor exhibited an excellent linear sensor response ranging from 10 to 800 μM and good reproducibility, stability, and selectivity with significant accuracy. These characteristics helped the sensor to accurately determine the creatinine levels in real human serum samples.