4 4 dinonyl 2 2 bipyridine

The BPE coated particles were used for growing poly (oligo (ethylene glycol) methyl ether methacrylate) (POEGMA) brushes from the MNPs’ surface through ATRP technique. 60 mg of BPE coated MNPs were suspended in 616 mmol THF. 0.134 mmol of copper chloride (Sigma-Aldrich) was added to the nanoparticle solution and the contents were sonicated until the solution was well dispersed and uniform. 2.8 kmol of oligo (ethylene glycol) methyl ether methacrylate (300 Da MW, Sigma-Aldrich) were added to the reaction. Prior to use, the monomer was purified to remove inhibitors using a prepacked inhibitor column (Sigma-Aldrich) for hydroquinone and monomethyl ether hydroquinone. The flask was sealed, set in an oil bath maintained at 60 °C, and N₂ gas was flushed while the reaction was continuously stirred. Once the solution had reached 60 °C, 0.4 mmol of 4–4’dinonyl-2–2’bipyridine (Sigma-Aldrich) were added to the reaction and the flask was again sealed and flushed with N₂ gas for 30 minutes. The reaction was let to run for overnight at 60 °C. On next day, the reaction was cool down and the MNPs were precipitated by centrifugation, and washed 3X with THF, 3X with acetone and 3X with Millipore water. Finally, the POEGMA coated MNPs (MNPs-POEGMA) were lyophilized and stored as powder for further experiments. The obtained MNPs-POEGMA are water soluble (Figure S1).