Summary of the shell thickness modification experiment results. Unless otherwise specified, the reaction conditions are as follows: TEOS – 22.5 μL; Rhodamine 110 – 80 μL of 1 mM solution or saturated solution. Unless otherwise specified, the shell was formed on to the 10 minute cores. As stated in the table, in some conditions fluorescence was only observed when nanoparticles formed aggregates.

Reaction time/conditions	Dye	Fluorescence	Photoblinking
10 h dry	N	Y	Y
10 h hydrated	N	Y	Y
8 h dry	N	Y	Y
8 h hydrated	N	Y	Y
6 h dry	N	Y	Y
6 h hydrated	N	Y	Y
4 h dry	N	Y	Y
4 h hydrated	N	Y	Y
2 h dry	N	Y	Y
2 h hydrated	N	Y	Y
2 h dry	Y	Y	Y
2 h hydrated	Y	Y	Y
2 h 5× citrate dilution core, dry	Y	At aggregates	N
2 h 5× citrate dilution core, hydrated	Y	At aggregates	N
2 h 10× citrate dilution core, dry	Y	At aggregates	N
2 h 10× citrate dilution core, hydrated	Y	At aggregates	N
2 h 1 mL SDS core, dry	Y	At aggregates	N
2 h 1 mL SDS core, hydrated	Y	At aggregates	N
2 h 5 mL SDS core, dry	Y	N	N
2 h 5 mL SDS core, hydrated	Y	N/A	N/A