Polyacrylonitrile/N-doped graphene quantum dots nanocomposite activity as SERS nanosensors for the detection of methylene blue

Surface-enhanced Raman spectroscopy (SERS) sensing effective substrates made of polymer and nitrogen-doped graphene quantum dots (N-GQDs) have attracted significant interest. SERS substrates are intensively used to detect pollutants/hazardous materials in various forms. In this study, we have integrated N-GQDs into polyacrylonitrile (PAN) polymer and fabricated the SERS active substrates, which facilitate the detection of methylene blue (MB). Scanning electron microscopic characterization demonstrated three-dimensional (3D) porous structural/morphology of the composite films. The porous structure formation might be due to solvent evaporation during film fabrication. The goal was to develop biocompatible and low-cost SERS substrates for MB detection. Synthesized 3D porous PAN/N-GQDs nanocomposite structure was shown to have an enhancement factor (EF) of 104 that of the polymer surface due to the multiple hotspot resonance effect, excitation dependent emission property and charge transfer induced in the structure. This phenomenon indicates that PAN/N-GQDs nanocomposite films have high potential as sensitive and selective nanosensors for the detection of MB. Current research results may lead to new and superior SERS substrates with increased sensitivity and selectivity.