Large Area Patterning of Highly Reproducible and Sensitive SERS Sensors Based on 10-nm Annular Gap Arrays

Applicable surface-enhanced Raman scattering (SERS) active substrates typically require low-cost patterning methodology, high reproducibility, and a high enhancement factor (EF) over a large area. However, the lack of reproducible, reliable fabrication for large area SERS substrates in a low-cost manner remains a challenge. Here, a patterning method based on nanosphere lithography and adhesion lithography is reported that allows massively parallel fabrication of 10-nm annular gap arrays on large areas. The arrays exhibit excellent reproducibility and high SERS performance, with an EF of up to 10⁷. An effective wearable SERS contact lens for glucose detection is further demonstrated. The technique described here extends the range of SERS-active substrates that can be fabricated over large areas, and holds exciting potential for SERS-based chemical and biomedical detection.