vacuum thermal evaporation. The obtained structure exhibits an LSPR at a resonant wavelength controlled by the nanosphere diameter (Figure ). ZIF-8 was then used to modify the plasmonic substrate, for which it was exposed for 30 min to methanolic solutions of zinc and 2methylimidazole mixed in a 1:2 ratio. These steps are typically considered as a single growth cycle, and by its repeating, it allows to further increase the thickness of the film. The whole approach for the growth of the MOF phase is called Liquid-Phase Epitaxial growth (LPE). After the growth of the MOF phase on the FON substrate, the authors observed a red shift of nearly 30% in the resonant wavelength. This significant shift highlights the intricate interplay between the plasmonic element and the MOF and underscores the importance of not only considering the individual optical response and performance of these components but also comprehending their complex interactions and synergistic effects. Once this interplay is understood, there also arises the question of the required amount of each component on the substrate that is needed to maximize the performance of the platform. It is known that MOF films present the so-called surface barrier phenomena, which hinders the adsorption of analytes once the outer part of the film is reacted with the sample. Unnecessarily thick MOF layers will then prolong the incubation time needed to reach the maximum signal. In addition, analyte molecules adsorbed beyond the decay length of the resonantly excited LSPs will not contribute to the SERS signal. Because of this, thickness becomes a critical parameter, which was for instance explored in the work of Koh et al. They assembled Ag nanocubes on a solid substrate by using the Langmuir-Blodgett technique and covered them by a thin ZIF-8 film grown by the LPE method previously described. The thickness of ZIF-8 overlayer was controlled between 8 and 287 nm by number of LPE cycles between 1 to 5, see Figure . This MOF-SERS substrate was tested for the analysis of 4-methylbenzenethiol (4-MBT) and the obtained dependence of SERS signal on the number LPE cycles is seen in Figure . It strongly increases with MOF deposition cycles until the 3 rd cycle, after which it levels. The obtained SERS signal intensity is a convolution of several factors including the thickness and structure of the porous MOF material that affects the loading with the target analyte. In addition, the plasmonic performance of the incorporated metallic nanostructures are also important, since they determines the extent of the electromagnetic field intensity enhancement contributing to the EM mechanism. The authors examined this aspect, by altering the packing density of the Ag nanocubes by adjusting the surface pressure in the Langmuir-Blodgett. They have found that SERS intensity increases with surface pressure, facilitating the enhanced plasmonic coupling within the Ag nanocubes, which translated into an increase of the analytical enhancement factor (AEF, see section 2.4) by one order of magnitude.