Profiling of exosomal microRNA (exo-miRNA) is very important for cancer diagnosis and treatment. However, rapid and sensitive determination the trace of exo-miRNA in clinical samples has not been developed. Herein, a robust electrochemical biosensor was proposed using multifunctional DNA tetrahedrons assisted catalytic hairpin assembly (MDTs-CHA) for exo-miRNA analysis. The MDTs-CHA, contained two multifunctional tetrahedrons (T1 and T2), leverage localized reaction and cascade amplification to enable rapid and ultrasensitive exo-miRNA analysis. Employing the MDTs-CHA, the electrochemical platform allowed quantitative measurement of exo-miRNA down to 7.2 aM in 30 min with good specificity. Furthermore, by profiling four tumor-associated exo-miRNAs (miR-1246, miR-221, miR-375, and miR-21) in a breast cancer cohort, this platform showed high efficiency (AUC: 0.989) and high sensitivity of 90.5% for breast tumors diagnoses, with 80% sensitivity for early diagnoses (stage I-IIa). Therefore, this platform has great potential in bioanalysis and clinical diagnostics.
Rapid electrochemical biosensor for sensitive profiling of exosomal microRNA
Zhang Y, Zhang X, Situ B, Wu Y, Luo S, Zheng L, Qiu Y. (2021) Rapid electrochemical biosensor for sensitive profiling of exosomal microRNA based on multifunctional DNA tetrahedron assisted catalytic hairpin assembly. Biosens Bioelectron [Epub ahead of print]. [abstract]