*2.7. Capping with 454-GE11*

For capping of MSN-NH2in-SHout samples, 10 μL Mal-PEG-GE11 reagen<sup>t</sup> (5 mg mL−<sup>1</sup> in H2O) was added to 100 μL 454 solution (5 mg mL−<sup>1</sup> in H2O) and shaken for 2 h at 37 ◦C. Then, 454-GE11 was mixed with 1 mL MSN suspension (1 mg mL−<sup>1</sup> in HEPES buffer) and again shaken for 2 h at 37 ◦C. Resulting MSN-454-GE11 samples were centrifuged (16,900 rcf, 10 min) and washed with water and HEPES buffer. The samples were redispersed in 2 mL HEPES buffer.
