Ultrasensitive SERS Detection of Cancer-Related miRNA-182 by MXene/MoS2@AuNPs with Controllable Morphology and Optimized Self-Internal Standards

Cancer has become a major killer threatening human health in today's society, and surface enhanced Raman spectroscopy (SERS) may provide a competitive choice for the sensitive detection of cancer-related miRNAs. In this work, a synergistic calibrated SERS strategy based on MXene/molybdenum disulfide (MoS2)@Au nanoparticles (AuNPs) with controllable morphology is suggested for the ultrasensitive detection of miRNA-182 by selecting the average intensity of its three own characteristic Raman peaks (at 382 cm(-1)and 402 cm(-1)corresponding to MoS(2)and at 611 cm(-1)corresponding to MXene) as a benchmark instead of additional beacon molecules. The linear goodness of fit (the determination coefficientR(2)) for this strategy is available in amounts up to 0.9995, which is significantly higher than that of single or double peak calibrated case, and thus improves the detection accuracy dramatically. Meanwhile, vertical MoS(2)nanosheets anchored on layered MXene can provide uniformly ordered sites for accommodating suitably sized AuNPs as hot spots with controllable particle gap of 2.2 nm, resulting in the maximum amplified SERS signal at 1362 cm(-1)generated by hairpin probe DNA with Cy5. A linear detection window from 10 amto 1 nmwith an ultralow detection limit of 6.61 amfor miRNA-182 is achieved.