Boron-/nitrogen-doped Ti3C2Tx MXene quantum dot-based sensor for determining an acute kidney injury biomarker

Abstract

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.