AG/AU nanocomposites on cellulose fiber matrices as plasmonic substrate for biosensing

Paper substrate provides cellulose micro-/nanofiber matrices for capillary-driven flow, and it also allows three-dimensional metal nanostructures for localized surface plasmon-based biosensing. However, previous works are still challenging in tailoring plasmon resonance wavelength in broad range. This work reports Ag/Au nanocomposites on cellulose fiber matrices as plasmonic substrate for biosensing such as metal-enhanced fluorescence (MEF), and surface-enhanced Raman scattering (SERS). Ag/Au nanocomposites were fabricated by using concurrent deposition of Ag and Au under composition regulation. This novel plasmonic paper substrate enables about two-fold enhancement of fluorescence signals, chromatographic MEF, and additional enhancement in SERS signals for detection of DNA base molecule.