Polyhedral Au Nanoparticle/MoO (x) Heterojunction-Enhanced Ultrasensitive Dual-Mode Biosensor for miRNA Detection Combined with a Nonenzymatic Cascade DNA Amplification Circuit

Key Words:SERS DETECTION; NANOSHEETS; MICRORNA; CANCER

Abstract:A novel homologous surface-enhanced Raman scattering(SERS)-electrochemical(EC) dual-mode biosensor based on a 3D/2D polyhedral Au nanoparticle/MoO (x) nanosheet heterojunction (PAMS HJ) and target-triggerednonenzyme cascade autocatalytic DNA amplification (CADA) circuit wasconstructed for highly sensitive detection of microRNA (miRNA). Mixed-dimensionalheterostructures were prepared by in situ growthof polyhedral Au nanoparticles (PANPs) on the surface of MoO (x) nanosheets (MoO (x) NSs) via a seed-mediated growth method. As a detection substrate,the resulting PAMS HJ shows the synergistic effects of both electromagneticand chemical enhancements, efficient charge transfer, and robust stability,thus achieving a high SERS enhancement factor (EF) of 4.2 x 10(9) and strong EC sensing performance. Furthermore, the highlyefficient molecular recognition between the target and smart lockprobe and the gradually accelerated cascade amplification reactionfurther improved the selectivity and sensitivity of our sensing platform.The detection limits of miRNA-21 in SERS mode and EC mode were 0.22and 2.69 aM, respectively. More importantly, the proposed dual-modedetection platform displayed excellent anti-interference and accuracyin the analysis of miRNA-21 in human serum and cell lysates, indicatingits potential as a reliable tool in the field of biosensing and clinicalanalysis.

Volume:95

Issue:24

Translation or Not:no