Simple and sensitive cerebral infarction related microRNA analysis via exonuclease-III assisted signal cascade

Accurate prognostic assessment and therapeutic monitoring are critical for improving outcomes in cerebral infarction, yet sensitive and robust analytical tools for reliable microRNA detection remain limited. Herein, we report a simple and highly sensitive analytical platform based on an exonuclease III (Exo-III)-assisted multi-signal amplification strategy for the detection of cerebral infarction-related microRNAs. A key innovation of this design lies in the use of a single detection probe that integrates both specific target recognition and signal amplification functions, effectively eliminating the need for multiple intricately designed probes and thereby enhancing assay robustness and reproducibility. Upon target recognition, an Exo-III-mediated multi-signal cycling cascade is triggered, enabling substantial signal amplification. The proposed method achieves a detection limit as low as 0.62 fM with a linear dynamic range spanning six orders of magnitude, alongside high specificity and excellent repeatability (coefficients of variation below 5%). Practical applicability was validated by recovery experiments and strong correlation with qRT-PCR (R² = 0.9943) using clinical samples. Furthermore, the method successfully distinguished miRNA expression levels among healthy controls, cerebral infarction patients, and those receiving Tongqiao Huoxue decoction treatment, underscoring its potential for both prognostic evaluation and therapeutic monitoring. With its simplicity, ultrahigh sensitivity, and robust performance, this platform holds great promise for low-abundance biomarker detection in clinical diagnostics and personalized medicine.