Beetle wing inspired fabrication of nanojunction based biomimetic SERS substrates for sensitive detection of analytes

Surface architecture belonging to flora and fauna is preferred because of their unique three dimensional micro/nanostructures, which can be utilised as novel support in SERS based chemical detection. In this work, we have fabricated biomimetic SERS substrates by replicating the wings of two different beetles with interesting surface morphology by employing soft lithography technique. Micro-bowls and nanogaps between globular microstructures on the replicated artificial wings surface have been utilised for aggregation of nanoparticles to create electromagnetic hot spots and enhanced interaction of nanoparticles with analyte molecules. The surface of these substrates has been engineered to form a homo-nanojunction between gold thin film and gold nanoparticles, which makes it more SERS active. The remarkable performance of these nano-junction based substrates was examined for SERS based sensitive detection of an organic dye, methylene blue, and a fungicide, carbendazim. This work paves way for the design and development of substrates using biomimetic approaches.