Silver nanoparticle arrays on track etch membrane support as flow-through optical sensors for water quality control

Silver nanoparticle arrays were assembled on the surface of polycarbonate track etch membranes using 3-aminopropyltrimethoxysilane as the chemical linker. The assembled arrays were submonolayer and reproducibly regular. The nanoparticle-modified membranes were characterized in terms of their hydraulic and optical properties and were evaluated as flow-through surface-enhanced Raman scattering (SERS) sensors for water quality monitoring. The membrane-supported nanoparticle arrays were found to be SERS-active with slightly lower but significantly more reproducible enhancements in comparison with enhancements afforded by source nanoparticle suspensions. Large enhancements of up to 10(5) were demonstrated due to preconcentration by recirculating analyte solution through nanoparticle-modified membranes that were shown to retain their hydraulic properties. The findings point to the promise of combining high specification SERS-active systems and the flow-through design for the development of analytical sensors for the trace detection of aqueous pollutants.