Fig. 3.

Laboratory-based optimization. (A) Setting up the annealing temperature of the PCR reaction. PCR products for different annealing temperatures (written at the top of each lane) were checked by 5 % agarose gel electrophoresis. (B) Effect of NaCl concentration on the colloidal stability of SNAs. Extinction ratio Ex₇₀₀/ Ex₅₂₀ was monitored as a function of NaCl concentration in the presence of 0.625 mM Mg²⁺ (Note that the UV–Vis spectra were recorded 10 min after adding NaCl and control was pure SNAs. Error bars are standard deviations n = 3). (C) Evaluation of assembly growth via time dependency of Ex₇₀₀/ Ex₅₂₀ ratio at the various amounts of linker. The Ex₇₀₀/ Ex₅₂₀ ratios higher than 0.8 are coincident with the red-to-purple color change which could easily be observed by the naked eye.