Three variants of the polymer bridge ("macromolecular glue") were synthesized for this work. For the first, a poly-(hexane-6-amine, propyl-3-dimethyloxysilane, nitrodopamine)acrylamide, which is tailored for the linkage of SiO 2 surfaces to transition metal-oxides (titania and iron in our case here), the synthetic details can be found in our earlier work. The following two polymers were synthesised to bridge noble metals and mixtures of noble metals and transition metal-oxides: poly-(hexyl-6-amine, ethylthiol, nitrodopamine)-acrylamide Pentafluorophenyl acrylate (pPFPAc) (502 mg, 2.1 mmol of active ester units) was dissolved in 10 mL dry DMF under N 2 at 50 • C. N-boc-hexanediamine hydrochloride (265 mg, 1.05 mmol) was dissolved in 2 mL dry DMF and subsequently added dropwise to the pPFPAc solution with an excess of triethylamine (0.45 mL, 3.23 mmol). After 1 hour of stirring at 50 • C under N 2 1 ml of a solution of aminoethanethiol (40.5 mg, 0.52 mmol) was added dropwise followed with 0.2 mL TEA. The nitrodopamine was added in excess after another reaction time of 1.5 hours, i.e. 309 mg (1.05 mmol) in 2 mL dry DMF combined with another 0.2 ml of TEA. The reaction vessel was left stirring overnight at 50 • C. DMF was reduced in a rotary evaporator and the product was redissolved in 12 ml of DCM. The N-Boc group of this crude product was removed by adding 4 ml TFA and stirring it overnight at room temperature. The solvents were evaporated, the polymer dissolved in 20 mL water, and dialyzed against water (Spectrapor3 membrane, MWCO 3.5 kDa) over the course of a week with multiple water changes. To obtain the final yellow-brownish polymer the final solution was freeze-dried. Yield: 278.9 mg.