MXene derived TiO2–ZnO nanocomposites and well-defined n-n heterojunctions for highly efficient lung cancer biomarkers detection

Enhancing the sensing properties of resistive sensors holds pivotal importance as a non-invasive technology for identifying lung cancer biomarkers. This study focused on the development of a robust sensing platform to effectively detect low-concentration biomarkers with low concentration. Ti3C2Tx MXene was prepared by HF etching and ZnO was successfully grown on the MXene nano-multilayers via hydrothermal method subsequently. TiO2–ZnO samples were obtained after the calcination step. Various characterization methods were applied to validate the structural integrity and formation of the TiO2–ZnO n-n heterojunction. The TiO2–ZnO sensor with a Ti:Zn atom ratio of 1:1 (TZ1) exhibited special sensing characteristics, which can be attributed to the higher activation energy (89.2 kJ/mol) and the more substantial interfacial contact areas between the two metal oxides. This architectural arrangement gives rise to the creation of numerous energy barriers, effectively hindering electron migration. Despite exhibiting the acceptable response, TZ1 can be applied in electronic nose systems to effectively detect lung cancer indicators with low concentrations (i.e., acetone, formaldehyde, NH3) in light of its high stability and steady signal-to-noise ratio.