Herein, we demonstrate the fabrication of a simple yet
highly efficient paper-based SERS substrate by loading gold
nanorods (AuNR) in a commercially available laboratory
filter paper. The SERS substrate demonstrated here can be
used by simply swabbing the surface of an object suspected
of exposure to a hazardous material. We demonstrate the
detection of less than 140 pg of 1,4-benzenedithiol (1,4-BDT)
residue spread over 4 cm2 surface by swabbing the AuNRloaded
paper on the surface. Previous attempts employing
filter paper exhibited limited sensitivity, possibly because of
the thin metal films (thermally evaporated or sputtered) or
poor control over the size and shape of the metal nanostructures
employed in these designs (23, 24). Apart from the
large enhancement, the uniform decoration of the nanorods
demonstrated here preserves the favorable attributes such as flexibility, conformal nature, and capillarity of the paper.
To the best of our knowledge, this study presents the first
SERS swab for rapid and efficient sample collection from
real-world surfaces with unprecedented sensitivity.