Fabrication of SERS-active structures via electrostatic deposition of colloidal gold nanoparticles on polymer microspheres

In the present study, we report on the fabrication and investigation of SERS active structures based on the polystyrene microspheres functionalized with gold nanoparticles. Successful deposition of the gold nanoparticles on the  microsphere surface has been confirmed using the scanning electron microscopy and the zeta potential measurements. The proof-ofconcept experiments have demonstrated the SERS effect with the average enhancement factor
of about 10³. The studied structures are stable, easy to fabricate, and ready for application in sensing.