Aminosilane-based functionalization of two-photon polymerized 3D SU-8 microstructures

► Two-photon polymerized SU-8 microstructures were coated with protein and Au nanoparticles. ► Protein coverage on the TPP microstructures' surface is quantified: it is about 35%. ► The method leaves the sub-micrometer features of the microstructures intact. ► Even gold nanoparticle distribution on all parts of the polymerized microtools is achieved. ► Optical tweezers enable use of Au-coated microtools in metal-enhanced spectroscopy.