Development of Gold Nanostars Doped Flexible Substrate for Polystyrene Microplastic Detection Using Surface-enhanced Raman Scattering (sers)

Microplastics are plastic fragments smaller than 5 millimeters, originating from primary sources such as manufactured beads and fibers and secondary degradation of larger plastic materials. As a significant environmental pollutant, microplastics require sensitive and efficient detection techniques. This study presents a simple and cost-effective surface-enhanced Raman scattering method using a flexible substrate composed of gold nanostars deposited on filter paper. Polystyrene particles with an average size of approximately 0.5 µm were used as a model microplastic pollutant to evaluate the performance flexible substrate. The surface-enhanced Raman scattering signal enhancement was analyzed using a benchtop Raman system with a 532 nm excitation wavelength, achieving a detection limit as low as 5 µg/mL and an enhancement factor of approximately 1300. The feasibility of detecting other microplastics, including polyethylene, polypropylene and polyethylene terephthalate, was assessed. The results demonstrate that the gold nanostar-based flexible surface-enhanced Raman scattering substrate offers a highly sensitive, portable, and cost-effective alternative for real-world microplastic monitoring in aquatic environments, outperforming conventional spectroscopic techniques.