Scalable manufacturing of mesoporous nanograting SERS sensors for ultrasensitive molecular detection

Here, we report an extreme manufacturing strategy for fabricating mesoporous nanograting gold films (MNGFs) with uniformly distributed mesoporous architectures, designed to generate abundant SERS hotspots for ultra-sensitive chemical detection. These MNGFs were prepared via the electrochemical deposition of a mesoporous gold film onto a nanograting template using polymer micelles as a sacrificial agent. Notably, the width between the gratings could be adjusted with precision by varying the electrodeposition time, optimizing the SERS hotspots and nanogap formation. The resulting SERS substrates achieved a limit of detection (LoD) of 1 pM for rhodamine 6 G (R6G), with an analytical enhancement factor (AEF) of 4.55 × 10⁹. To evaluate their performance, the MNGFs were employed to detect thiophenol (TP), serving as a safe simulant for thiol-based analytes. Remarkably, the substrates exhibited exceptional sensitivity, achieving a limit of detection of 81 aM. Furthermore, the MNGFs facilitated gas-phase detection of TP at concentrations as low as 3.73 parts per billion (ppb), underscoring their practical applicability. Moreover, the MNGFs demonstrated excellent spatial uniformity, with a relative standard deviation (RSD) of 9.68%, and could be reused up to four times, maintaining consistent SERS signals and enhancement. Overall, the 3D mesoporous nanograting architecture offers a scalable, reproducible, and high-performance sensing platform, representing a promising advancement in precision manufacturing for real-time, on-site hazardous chemical monitoring.