Ho₂O₃-TiO₂ Nanobelts Electrode for Highly Selective and Sensitive Detection of Cancer miRNAs

The design and engineering of effective electrode materials is critical in the development of electrochemical sensors. In the present study, Ho₂O₃-TiO₂ nanobelts were synthesized by an alkaline hydrothermal process. The structure and morphology were investigated by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) measurements. The Ho₂O₃-TiO₂ nanobelts showed a distinctly enhanced (004) reflection peak and rough surfaces and were used for the electrochemical selective sensing of various cancer miRNAs, such as prostate cancer miR-141, osteosarcoma miR-21, and pancreatic cancer miR-1290. Voltammetric measurements showed an oxidation peak at +0.4, +0.2, and +1.53 V for the three different cancer biomarkers, respectively, with the detection limit as low as 4.26 aM. The results suggest that the Ho₂O₃-TiO₂ nanobelts can be used as active materials to detect early cancers, for in vitro screening of anticancer drugs, and molecular biology research.