Oriented interfacial self-assembled SERS platform with dual nucleic acid amplification for detection of MiRNA 21

Liquid‒liquid interface self-assembly was recently proposed to be an efficient strategy for surface-enhanced Raman scattering (SERS) detection. Traditionally, most of the research focuses on the self-assembly of single morphology and homogeneous materials, which are susceptible to the rotation of materials in the liquid phase due to the interference of Brownian motion and the external environment, causing poor stability. In this work, we introduced ternary Ag–Au–SiO2 nanoparticles to a liquid‒liquid self-assembled SERS platform, utilizing the differences in hydrophilicity of the materials to achieve oriented interfacial arrays, improving the stability of the self-assembled SERS substrate. To enhance the detection efficiency, a dual nucleic acid amplification strategy was designed to reach ultrasensitive detection of target microRNA 21 with a detection limit of (LOD) of 1.41 aM, providing a foresight for the practicability of the two-phase interfacial SERS platform.