Abstract:
We discuss a facile, fast, simple, and reproducible fabrication method to modulate the structural morphology of
the SERS substrate to improve its performance. The interconnected Au network structure named as nanoporous
Au (NP–Au) is prepared by the dealloying method and further exposed with varied laser power in order to check
the effect of power variation on the morphology as well as on the SERS performance. The effectiveness of the
substrate has been tested by detecting Rhodamine 6G as a probe molecule. The Raman results show a good linear
relationship with the laser power increment up to 3.2 mW and after that, the signal becomes saturated for a
further increment in the power. The substrate is able to enhance the signal up to 102
-fold as well able to show all
the characteristic peaks without any damage to the probe molecule. Morphological identification reveals that
different sizes and shapes of the pores (open, diffused, and interlinked) are responsible for the SERS signal
enhancement. Subsequently, the sensitivity of SERS substrate has been examined and the result suggested that
the optimal concentration of Rhodamine is 10− 9 M. Furthermore, the substrate possesses good uniformity by
representing a relative standard deviation value of less than 15 %. The substrate potential for real-world
application has been examined by identifying urea (pesticide) molecules. The prepared nanoporous substrate
is able to show a well-intensified signal with ~16-fold enhancement compared to planar Silicon substrate.
