Methods for Fabricating Surface-enhanced Raman Spectroscopy Substrates

A process or method of fabricating SERS active substrates all by atomic layer deposition (ALD) on commercial glass filter paper substrates:

• comprising first depositing a continuous and conformal dielectric layer for tuning target wavelength of the localized surface plasmon resonance (LSPA) or as the chemical wetting/adhesion layer;
• secondly, depositing a conformal nanostructure wrapped around all 3 dimensional (3D) porous fibers in thickness direction all the way to form high density 3D isolated island-like nano-sized metallic particles and the nanostructure has to be tuned to show maximal intensity of LSPA peaks;
• immediately after the second step, a dielectric passivation layer of sub-nanometer in thickness to be deposited conformally on those nanoparticle surface to sustain long-shelf life of the SERS active substrates when exposed to air.