Polyvinyl Alcohol Films Loaded with Silver Nanostructures with Different Sizes and Shapes with Tuneable Plasmonic and Electric Properties. A Spectroscopic Study

Abstract

To study the effect of the incorporation of silver nanoparticles into polyvinyl alcohol (PVA) films on their optical and conducting properties, silver nanostructures with different sizes covering from spherical to polyhedral shapes were synthesized and embedded into the polymer. The sizes of the obtained silver nanostructures were analyzed by Dynamic Light Scattering (DLS), which exhibited high stability, attributed to their surface potential. Multimodal distributions suggest changes in shape ranging from spheres (~40 nm) to prisms (~100 nm), which was confirmed by Scanning Electron Microscopy (STEM/SEM) analysis. By embedding these nanostructures in polyvinyl alcohol (PVA), AgNPs loaded PVA polymer films were prepared, exhibiting a hypsochromic shift in the surface plasmon resonance band of the nanostructures. For conductivity determination of AgNPs loaded PVA polymer films, Electrochemical Impedance Spectroscopy (EIS) was used. The results indicated that the conductivity of the samples is highly dependent on the size and shape of the AgNPs embedded into the polymer, resulting in higher conductivity for smaller silver nanostructures.

Common Transition Metal Oxide Nanomaterials in Electrochemical Sensors for the Diagnosis of Monoamine Neurotransmitter‐Related Disorders

“…The significant disparity between the electronic conductivity of PANI (1×10 À 6 S cm À 1 ) and poly(vinyl alcohol) (1.7×10 À 9 S cm À 1 ) contributed to the large difference between these limits of detection. [143,145] The combination of ZnO NPs and carbon nanomaterials (e. g. graphene oxide (GO), reduced GO, [146] graphene, [147] carbon, and CNTs) has facilitated DA detection at the subnanomolar level. The figures of merit of a ZnO/reduced GO, a ZnO/graphene, a ZnO nanorod/electrochemically reduced GO composite, and a reduced GO/ZnO modified electrodes in Table 3 show that the variation in the chemical properties of graphene could provoke a significant difference in the electrocatalytic activity of a ZnO NPs/GO-based sensors towards DA oxidation to DA-o-quinone.…”

“…However, the limit of detection for DA at ZnO/PANI/carbon paste electrode (29 nM) is significantly lower than that of a fluorine‐doped tin oxide electrode/NP‐ZnO/poly(vinyl alcohol) (5000 nM). The significant disparity between the electronic conductivity of PANI (1×10 −6 S cm −1 ) and poly(vinyl alcohol) (1.7×10 −9 S cm −1 ) contributed to the large difference between these limits of detection [143,145] …”