you can read the following:

1. Article Controlling Light, Heat, and Vibrations in Plasmonics and Phononics

2. https://patents.google.com/patent/WO2016115542A1/en

3. Article Plasmonic Nanofabrication Through Optical Heating

It is easy to excite Localized Surface Plasmonic Resonance (LSPR) in metal nanostructures if compared with propagating SPP. LSPR results in heating and is used for treating cancer cells. Although, I have not come across any research article doing this via LED but since excitation of LSPR does not depend on angle of excitation, thus I think it is possible to excite it with even LED provided there are no scattering (or any other) losses.

You can follow the links shared below:

Article Controlling Light, Heat, and Vibrations in Plasmonics and Phononics

Article Hot electron and thermal effects in plasmonic photocatalysis

Hello Philipp Harder,

To answer your question: the photothermal temperature depends on the rate of energy input and the rate of energy loss to the surrounding. Although plasmonic nanoparticles have very high absorption cross sections, the heat generated is also lost immediately to the surrounding. Theoretically, an isolate Au or Ag nanoparticle in water requires quite high laser intensity at the resonance wavelength 1 mW/μm2 to achieve a local temperature of, let's say, 50 oC. This is like a million times the sun intensity. I did these calculations in two of my papers:Article Silver-Gold (Au-Ag) Bimetallic Nanoparticles: Alloy Nanopart...

Article Plasmonic coupling in 2D Gold Nanoparticle Clusters/Assembli...

It has also been shown that a nanorod or a nanotriangle will have higher photothermal temperature than nanospheres due to higher absorption cross section. But this will still requite such a high intensity light source. The interesting aspect of plasmonic photothermal heating is the intense heating at nanoscale for targeted thermal therapy.

Now, whether you can achieve such a temperature with LED light depends on what is the mechanism you are putting in place to retain the heat. If you thermally isolate the nanoparticles (colloid or embedded in an insulating solid matrix), then a low power light source will also eventually heat up to a high temperature. This will not be any different from solar cookers for instance where a black surface can be used to capture heat and a glass box to reduce radiation losses. So it is possible, but the use of plasmonic nanoparticles for the heating needs to be justified.