Facile Microfluidic Fabrication of 3D Hydrogel SERS Substrate with High Reusability and Reproducibility via Programmable Maskless Flow Microlithography

Abstract In the field of surface‐enhanced Raman scattering (SERS), advances in nanotechnology and surface chemistry have contributed to fabricating the metal substrates with highly sophisticated architectures and strong binding affinity to target molecules which enhanced the sensitivity to target molecules. However, the elaborate yet complicated steps for the synthesis, patterning, and surface modification of metal substrates have often resulted in compromising the reliability, reproducibility, and reusability as SERS substrates. Here, a fully programmable and automated digital maskless flow microlithography process that spatiotemporally controls the fluid flow, UV irradiation, and the shape and location of SERS polymer matrix is provided to fabricate a reliable, reproducible, and reusable hydrogel‐based 3D SERS substrate. The SERS substrates are located inside the microfluidic device in…