Design of polymers and plasmonic nanostructures. The proposed concept was pursued with two types of photo-crosslinkable polymers shown in Figure , which form a polymer network via MPC and subsequently a hydrogel after swelling with water. The copolymer poly(N,Ndimethylacrylamide-co-acylamido-3-hydroxyanthraquinone), abbreviated as poly(DMAA96-co-AAHAQ4), was chosen for the preparation of rigid hydrogel structures, which is ascribed to an apparently higher crosslink density due to a high ratio of anthraquinone-based photo-crosslinking units (4 % AAHAQ polymerization feed) in the polymer backbone. In addition, the terpolymer The MPC process of the polymer chains at plasmonic hotspots was induced by scanning the polymer-embedded AuNP array with a focused NIR fs laser beam of a wavelength λL that is resonant with LSPs supported by AuNPs at a wavelength of λLSPR, as schematically presented in overlayer were scanned "line-by-line" with a focused NIR fs laser beam using a power of PL = 4 mW and writing speed of 2.5 × 10 3 lines per second. This condition was below the threshold for MPC without plasmonic amplification, as can be seen in the details on the "line-by-line" writing with the commercial Nanoscribe lithographer in the "Materials and methods" section. After the MPC recording and ethanol rinsing step, the patterned structures were characterized with the AFM, and Figure shows the obtained height topography with detailed cross-sections presented in the height drops to half of its maximum, see Figure ). This value is comparable to the distance probed by LSPs simulated for the same AuNP reaching about 50 nm (distance from the Au wall where the electric field amplitude drops to half of its magnitude, see Figure ). In order to rule out that the polymer features appearing after the irradiation with the fs pulsed laser beam are associated with the effect of burning, and to confirm that MPC lead to a polymer network that forms a hydrogel after swelling with water, elastic properties were evaluated by mapping of the Young's modulus in air (Figure ) and in water (Figure ). Both micrographs reveal that around the hard metallic nanoparticles (with Young's modulus > 20 GPa) a belt-shaped region with lower stiffness occurs. The evaluation of these data using the elastic contact model according to Hertz with the Sneddon extension for the tip geometry was carried out.