Bioinspired superwetting SERS substrate based on femtosecond laser processing: Principles, methods, and applications

The growing demand for surface‐enhanced Raman scattering sensors in biochemical detection, environmental monitoring, microfluidics, and other fields has promoted the development of highly sensitive and stable substrates. Femtosecond laser‐fabricated surfaces with controlled wettability, unique micro/nanostructure designs, and tunable extreme wetting properties can significantly enhance the signal amplification and reproducibility of surface‐enhanced Raman scattering techniques. In this review, we offer a comprehensive overview of recent advancements in surface‐enhanced Raman scattering techniques based on superwetting surfaces fabricated by femtosecond laser processing, including fully superhydrophobic surfaces, hybrid wettability surfaces, and visual localization surfaces. The main research areas, such as pattern optimization, dynamic measurements, hot spot enhancement, and stability improvement, are highlighted. We also summarize the practical applications of surface‐enhanced Raman scattering in chemical detection, microfluidic control, medical diagnosis, and food safety evaluation. Finally, the current challenges and limitations in the development of femtosecond laser‐processed superwetting substrates for surface‐enhanced Raman scattering are described.