Planar monolithic porous polymer layers functionalized with gold nanoparticles as large-area substrates for sensitive surface-enhanced Raman scattering sensing of bacteria

Abstract

For the first time, large-area surface-enhanced Raman scattering sensing active substrates using porous polymer monolithic layers have been successfully prepared. Our approach includes a simple photoinitiated polymerization process using glycidyl methacrylate and ethylene dimethacrylate in a glass mold, followed by a chemical reaction of the epoxy functionalities leading to thiols, and the attachment of preformed gold nanoparticles. We demonstrated that this very simple process produced uniform and reproducible large area surfaces that significantly enhance sensitivity of Raman spectroscopy. Experiments were also carried out that confirmed preferential adsorption of living bacteria Escherichia coli from a very dilute solution on the surface of the monolithic layer, and immediate detection of the captured microorganisms using the SERS spectrum.

Keywords: Bacteria; Gold nanoparticles; Monolithic layer; Porous monolith; Surface-enhanced Raman scattering.