Nanozyme-active Au@Pt NRs array SERS platform based on a recognition competition strategy for convenient and ultrasensitive detection of miR-106a-5p associated with cerebral infarction

In this study, we constructed a SERS assay platform that can be used for the ultrasensitive detection of cerebral infarction (CI)-associated miR-106a-5p based on the recognition competition strategy and the highly efficient catalytic activity of Au@Pt NRs nanoenzymes. When the target miR-106a-5p is present in the detection solution, it binds to the nucleic acid aptamer (cDNA), leading to the detachment of its complementary strand (H₁) carrying Au@Pt NRs from the surface of AuNHs, and the oxidation of TMB is reduced, resulting in the decrease of SERS signal. In addition, this method enables single-step, ultrasensitive detection of target miRNAs in patient serum with a limit of detection (LOD) of 0.96 fM, which is consistent with the results of real-time quantitative polymerase chain reaction (qRT-PCR) and fluorescence. This method provides a novel approach for the effective detection of miRNAs, which is of great clinical value for the early detection of CI.