UC Santa Cruz

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.