0000000000433720
AUTHOR
Rachid Gradess
Localized surface plasmon resonance sensor based on Ag-PVA nanocomposite thin films
In this work we demonstrate the use of nanocomposite thin films of poly(vinyl alcohol) with embedded silver NPs for chemosensing purposes. Silver NPs are in situ synthesized inside polyvinyl alcohol during the bake step of the formation of a nanocomposite thin film. The polymer in the nanocomposite provides an appropriate chemical and electromagnetic environment for metal NPs in order to interact with and hence detect the chemical species. A limit of detection below 20 nM is found when detecting 2-mercaptoethanol as the analyte, when measuring spectral changes (peak wavelength, linewidth and intensity) in the Localized Surface Plasmon Resonance. Potential qualitative and semi-quantitative s…
Scalable heterogeneous synthesis of metallic nanoparticles and aggregates with polyvinyl alcohol
Here we report on a new route to synthesize colloidal silver and gold nanoparticles, potentially scalable for massive nanoparticle-production. This method is based on the microwave-assisted heterogeneous reduction of the metal salts with polyvinylalcohol. The reaction is carried out in alcohols, which are non-solvents for polyvinylalcohol. Nanoparticles can be very easily separated by filtration. The reaction kinetics are extremely fast. Size-controlled formation of nanoparticle agglomerates is accomplished with a seed-mediated synthesis of nanoparticles upon MW exposure.
Optical properties of different polymer thin films containing in situ synthesized Ag and Au nanoparticles
Here we report on the in situ synthesis of Ag and Au nanoparticles inside several polymer matrixes by solid-state chemical reduction of a metallic salt. Poly(ethyleneimine) (PEI), poly(hydroxyethyl methacrylate) (PHEMA), poly(vinylpyrrolidone) (PVP), novolak, poly(4-vinylphenol) (P4VP), poly(4-vinylphenol)-co-(methyl methacrylate) (P4VP-co-MMA) and poly(styrene-co-allyl alcohol) (PS-co-AA) were able to reduce Ag(I) and Au(III) to the corresponding nanoparticles during the baking process. The nanoparticle diameters of Ag and Au were found to range from 2 to 25 nm. TEM also indicated a uniform distribution of nanoparticles embedded in the thin film. This approach is suitable for controlling t…