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This paper discusses how the nanoparticles of a silver citrate hydrosol affect the fluorescence and phosphorescence intensity and lifetime of anionic and cationic dye molecules. It is found that, depending on the nanoparticle concentration of the silver hydrosol, there is both amplification and quenching of the fluorescence and phosphorescence of the molecules. Interaction mechanisms are observed between excitation by the molecules and by the silver nanoparticles.

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Abstract This work presents the dependences of the absorption intensity of the acid-soluble chitosan biopolymer films in the infrared (IR) region of the spectrum on the concentrations of silver and gold nanoparticles (NPs) of different morphologies. The interaction mechanisms in the vibrational spectra overlapping area of the silver NPs and chitosan molecules (2500–3500 cm−1) were observed. The influence of the metal NPs on the dipole moments of the OH-, NH3+- and CH-chitosan molecule group oscillations was established. This interaction leads to a linear increase of the IR absorption intensity with an increase of the silver nanoparticle concentration, synthesized by the citrate and borohydride methods. The presence of silver and gold ablative NPs in the chitosan films demonstrates the IR absorption intensity exponential decrease with the metal NPs’ concentrations.

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