Rutile Titanium Dioxide Facet Heterojunction Nanostructure with Double-Stranded Specific Nuclease for Photoelectrochemical MicroRNA-155 Detection

In this article, a quick and sensitive photoelectrochemical biosensing platform was successfully fabricated for microRNA (miRNA)-155 detection based on the rutile titanium dioxide facet heterostructure (FH-TiO₂). Nanosheets with different crystal faces (111) and (101) exposed are assembled on rutile TiO₂ nanorods (TiO₂ NRs) to serve as a TiO₂ facet heterostructure (FH-TiO₂) platform. In this assay, double-stranded specific nuclease was used to remove the double strands formed by the target RNA and probe DNA and release the target DNA for the next cycle so that the subsidiary DNA (S1) can hybridize with the residual base strands of probe DNA, which will introduce the SiO₂ nanoparticles attached to the electrode surface. Infinitesimal targets could initiate huge change in the electrode signal via an enzyme-assisted target cycling procedure. A satisfactory performance with a linear range (0.1 pM to 10 nM) and the detection limit (0.025 pM, LOD = 3*σ/S) was obtained for the miRNA-155 detection, implying a promising application in the biological analysis of related diseases and clinical diagnosis.