Fig. S5.

Percentage of coverage of TBA-29 aptamer on 60 nm AuNPs as a function of time. When particles are freshly functionalized with TBA-29 and NBT, there is an average of 1,830 ± 335 TBA-29 strands per particle. The theoretical maximum coverage is ≈1,880 strands of TBA-29 per 60-nm particle, assuming the footprint of the TBA-29 G-quadruplex to be 3 × 2 nm². As particles are stored, the coverage decreases from full coverage to around 50% by week 4. For consistency, particles are always made fresh and used immediately for the assay.