Tailorable janus plasmonic SERS platform with hotspots integrating and analytes enriching property for multiple sensing

Electromagnetic hotspot engineering plays a crucial role in surface-enhanced Raman scattering (SERS) biosensors. However, the construction of optical hotspots with high density and the concentration of analytes into hotspot centers remain challenging tasks. Additionally, achieving high sensitivity and signal reproducibility in SERS biosensors is an ongoing challenge. In this study, we utilise Janus micro/nano arrays to develop a superhydrophobic SERS platform. The high roughness of these arrays facilitates the distribution of rich hotspots ranging from nano to microscale and encourages the concentration of analytes within hotspot centers. The Janus plasmonic micro/nano arrays were meticulously crafted through the synergy of site-specific growth and instant interfacial assembly of nanoparticles (NPs). In the realm of SERS measurements targeting organic dyes in river water, our sensing platform demonstrates high sensitivity (limit of detection (LOD): 10−9 M) and signal reproducibility (relative standard deviation (RSD)=4.25%). Furthermore, the SERS platform exhibited remarkable sensitivity to multiple dyes in river water. Thus, our superhydrophobic SERS platform lays the groundwork for sensitive analysis in diverse fields such as environmental analysis and healthcare monitoring.