Hybrid nanoassembly with two-tier host-guest architecture and regioselective enrichment capacity for repetitive SERS detection

Due to the challenge of controlling analyte-particle and particle-particle distances in the SERS detection matrix, the most promising nanosensor systems still suffer from difficulties in increasing the sensing stability and repeatability. Herein, a host-guest assembly strategy was developed to build two-tier nanoarchitecture based SERS device for a highly repetitive detection system. Specifically, gold nanoparticles were installed on the outer surface of mesoporous polydopamine nanoparticles and modified with a self-assembled monolayer of 11-Mercapto-1-undecanol to drive the regioselective enrichment of analytes in the mesopores. Subsequently, the host-guest nanosensor particles were assembled into a uniform coffee ring pattern (~4 mm in inner diameter and 500 µm in width) on the surface of a porous host (polyvinylidene fluoride film with a pore size of 0.45 µm) through fast particle packing (20 s) driven by water infiltration in membrane pores. Finally, the sensing system achieved highly repeatable (RSD 3.1%−3.4%) analysis of organic dyes (limit-of-detection, LOD 24.1–59.6 fM) and miRNA (LOD 308.5 fM). The nanoassembly platform with distance constraint and enrichment effects is expected to pave a new avenue for interfacial engineering strategies of SERS sensors. [Display omitted] •Two-tier host-guest assemblies were constructed for repetitive SERS detection.•Dye and DNA analytes were enriched in mesoporous polydopamine NPs with surface Au NPs.•Droplet on porous PVDF film resulted in fast formation of uniform coffee ring pattern.•The distance constraints of SERS elements enable highly reproducible analysis.