In situ synthesis of gold nanoparticles (AuNPs) in butterfly wings for surface enhanced Raman spectroscopy (SERS).

Recently, surface enhanced Raman spectroscopy (SERS) has been widely studied for chemical and biological sensing. SERS substrates combined with photonic architectures have attracted more and more attention. Photonic architectures in butterfly wings are too complicated to fabricate with either "top-down" or "bottom-up" approaches. Herein, we developed a simple, reproducible, inexpensive and green method to fabricate SERS substrates from different butterfly wings where the component chitosan/chitin was utilized as in situ reducer to synthesize gold nanoparticles in natural 3D photonic architectures. The SERS performances of three butterfly wings are compared. And the results show that a SERS substrate based on M. menelaus is better than the other three substrates, which could detect 10-9 M 4-ATP and has the lowest RSD and moderate SNR. In situ synthesis of AuNPs in butterfly wings with photonic architectures paves the way for fabricating multiple SERS substrates based on natural materials.