Publication details
Streamlined Fabrication and Acoustofluidic Purification of Silver-Decorated Polystyrene Microspheres (PS-AgNPs) for SERS Applications
| Authors | |
|---|---|
| Year of publication | 2026 |
| Type | Article in Periodical |
| Magazine / Source | ACS APPLIED NANO MATERIALS |
| MU Faculty or unit | |
| Citation | |
| web | https://pubs.acs.org/doi/10.1021/acsanm.5c04981 |
| Doi | https://doi.org/10.1021/acsanm.5c04981 |
| Keywords | acoustofluidics; immobilization; PS-AgNPs; polystyrene; silver nanoparticles; sorter; surface-enhanced Raman spectroscopy; wet etching |
| Attached files | |
| Description | Composite microspheres of polystyrene and silver (PS-AgNPs) are highly valuable materials for catalysis, sensing, and antibacterial applications, yet their fabrication and subsequent purification remain challenging. This work presents a streamlined pathway for PS-AgNPs production, initiated by our finding that commercially available polystyrene (PS) microspheres (diameters >= 5 mu m) anchor residual stabilizing polymeric structures that spontaneously facilitate the firm attachment of premade silver nanoparticles. The purified PS-AgNPs microspheres were evaluated as potential surface-enhanced Raman spectroscopy (SERS) substrates using adenine and thiamine as probe molecules, showing uniform SERS responses (coefficient of variation approximate to 10%) and limits of detection (LOD) of 100 nM and 1 mu M, respectively. This demonstrates strong plasmonic activity that is suitable for sensing applications. While the synthetic approach is highly straightforward, it inherently creates a need to remove free and weakly attached nanoparticles, a critical step for PS-AgNPs practical application. We innovatively address this challenge by developing an acoustophoretic-based glass microfluidic device. Notably, the microchip was fabricated by using isotropic wet etching, a highly accessible method traditionally considered unsuitable for the precise geometries required for acoustophoresis. The separation principle relies on differential acoustophoretic migration, where larger PS-AgNPs microspheres are redirected into a collection outlet, while loose nanoparticles continue into the waste output, ensuring a high-purity final product. |