| In the field of forensic science, discovered materials that could potentially be used as evidence are screened using presumptive and confirmatory tests before the samples are subjected to DNA analysis. Both of these tests have drawbacks associated with their use, such as being prone to false positive and negatives. Only one biological fluid can be analyzed using one of these tests at a time. Further, these tests are destructive to the sample, meaning no further analyses could be performed on the same sample portion. Herein, we report the functionalization of commercially available nylon evidentiary swabs to serve as a SERS-active medium for non-destructive confirmatory analysis of seminal fluid by attaching silver nanoparticles grown via the hydrogen reduction method to the fibers. The resulting swabs have been analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES) and electron microscopy to assess the silver nanoparticle coverage. The two model dye compounds crystal violet and tris(2,2'-bipyridyl)ruthenium(II) chloride were analyzed using SERS as a proof of concept and examination of SERS enhancements, respectively. The research includes the study of the effects of swab fabrication on surface coverage, particle size and spacing, and Raman and SERS spectral enhancement of the two model dyes and seminal fluid. Efforts to maximize seminal fluid SERS signal while exploring the effect of swab storage is also presented. |
