Rapid and Sensitive Detection of Non-Small Cell Lung Cancer-Related Micrornas by a Pump-Free Sers Microfluidic Chip

In this paper, a pump-free and multi-channel surface-enhanced Raman scattering (SERS) microfluidic chip proposed for the rapid and sensitive detection of miR-92a and miR-339-3p, two microRNAs (miRNAs) related to non-small cell lung cancer (NSCLC). The sample solution can flow along the microchannel into the reaction zone during the assay, driven by the capillary force generated by the comb-like structured channel. When the target strand is present in the sample, a one-step pairwise hybridization reaction occurs with the corresponding hairpin structure DNA (hpDNA) labeled with Raman signal molecules, and the SERS signal is amplified by the ordered Au-Ag nanobowl (Au-AgNBs) array substrate. The detection limits of miR-92a and miR-339-3p in serum were 44.36 aM and 63.58 aM, respectively, using this method, with a detection and analysis time of only 8 minutes. The microfluidic chip showed good specificity, reproducibility, and stability. Finally, the method was used to detect miR-92a and miR-339-3p in the serum of NSCLC clinical samples, and the results were consistent with the quantitative real-time polymerase chain reaction (qRT-PCR). In conclusion, this pump-free SERS microfluidic chip is a very promising tool for detecting miRNA expression levels, which can help in the early diagnosis and prognosis of NSCLC.