Bacterial Nanocellulose‐Based Flexible Surface Enhanced Raman Scattering Substrate

Owing to high purity, simple surface chemistry, and 3D nanofibrous structure, biosynthesized bacterial nanocellulose (BNC) is a highly attractive biomaterial for a wide range of applications. Conventional cellulose‐based laboratory filter paper, adsorbed with plasmonic nanostructures can be employed as a flexible surface enhanced Raman scattering (SERS) substrate. In this work, a BNC film‐based SERS substrate fabricated by gravity‐assisted filtration method is reported. The 3D porous structure of BNC facilitates uniform and dense adsorption of plasmonic nanostructures on the surface and in subsurface regions, which results in large SERS enhancement. Furthermore, significantly lower surface roughness of BNC compared to conventional filter paper results in an excellent uniformity of SERS activity across the entire substrate. Harnessing the smooth surface of BNC, it is shown that BNC‐based SERS substrate serves as an ideal platform for collection, detection, and recognition of bacteria. The 3D plasmonic BNC composites demonstrated here are highly attractive for a broad range of applications including sensing, catalysis, and energy harvesting.