Boron-/nitrogen-doped Ti₃C₂T _x MXene quantum dot-based sensor for determining an acute kidney injury biomarker

In this study, boron/nitrogen-doped Ti₃C₂T _x MXene quantum dots (BNMQDs) were synthesized via a hydrothermal technique and successfully brush-coated on a carbon fiber paper (CFP)-based electrode to detect creatinine (crt). The prepared MQDs were characterized by employing transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), and X-ray diffraction (XRD) analysis to study their physicochemical properties. The electrochemical performance of the modified CFP-based sensors toward crt detection was analyzed by employing cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Ti₃C₂T _x MQDs were prepared using the hydrothermal method and further doped with B and N using boric acid and p-phenylene diamine, respectively. The morphology of the obtained BNMQDs was quasi-spherical and exhibited uniform size with scattered particle sizes ranging from 5 to 9.5 nanometers. Owing to several surface-active sites, edge effects, and quantum confinement, the synthesized MQDs demonstrated enhanced electrooxidation of crt. Compared to BMQDs and NMQDs, BNMQDs showed superior sensing performance, with a wide linear range of 0.104-135 μM and an LOD of 34.53 nM. The fabricated electrode also demonstrated high stability, reproducibility, and selectivity for the electrocatalytic oxidation of crt in real samples.