Facile fabrication of superhydrophobic gold loaded nanoporous anodic alumina as surface-enhanced Raman spectroscopy substrates

A facile method of creating a sensitive and inexpensive superhydrophobic nanoporous anodic alumina (NAA) based surface-enhanced Raman spectroscopy (SERS) substrate is reported. A superhydrophobic NAA was created by coating polydimethylsiloxane on NAA via polymer evaporation technique which further coated with gold to fabricate NAA-based superhydrophobic SERS substrate. NAA and nanopatterned aluminum with varying pore properties were used for the SERS studies using rhodamine 6 G as the model analyte. The limit of detection was calculated for the SERS substrate and found to be as low as 146.3 pM. The analytical enhancement factor was found to be 6.9 × 105 successfully demonstrating the potential use of NAA-based superhydrophobic substrate as a SERS substrate. The substrates displayed good spatial reproducibility with a relative standard deviation of 12.62%, demonstrating the potential use of such substrates in chemical and biological sensing applications. The method reported is general and provides a simple and cost-effective approach for generating efficient SERS platforms for trace molecular sensing.