I think it is possible to solve this problem via sedimentation of aerosol particles generated in, say, spark-discharge generator. We have such a generator in our laboratory, also we have an experience in aerosol filtration and manufacturing polymer fiber HEPA filters.

I know that this has been done on nanocellulosic fibers using physical adsorption methods. You can find more details in this article.

Journal of Materials Chemistry C

Volume 1, Issue 47, 21 December 2013, Pages 7963-7972

I used to deposit metallic colloids by putting a drop of the colloidal solution on the hst substrate. Then i added a drop or two of HF (10%). The colloids immediately fall on the substrate by mean of sedimentation.

Naturally your fibers have to be resistent with respect to HF and you need to get a liquid solution with your metallic particles in suspension.

Prof. Juan Hinestroza has been doing this with notable success. For instance DOI 10.1007/s10570-012-9763-8

Dear Mojtaba,

I have coated titania nanoparticles and hydroxy apatite nanoparticles on nanofibrous scaffolds by using electrospraying. Plz check my articles:

https://www.researchgate.net/publication/44595562_Simultaneous_electrospin-electrosprayed_biocomposite_nanofibrous_scaffolds_for_bone_tissue_regeneration?ev=prf_pub

https://www.researchgate.net/publication/50941315_Electrospun_polyimidetitanium_dioxide_composite_nanofibrous_membrane_by_electrospinning_and_electrospraying?ev=prf_pub

Cheers

Article Simultaneous electrospin-electrosprayed biocomposite nanofib...

Article Electrospun Polyimide/Titanium Dioxide Composite Nanofibrous...

You can also do surface modification:

1. Do plasma treatment on your fibers surface.

2. Functionalize your metal nanoparticles with polyethylenimine or a suitable polymer

3. Apply the functionalized nanoparticles on your scaffold...

please go through the attached paper...many researchers are doing these kind of works.