Figure 2.

UV-Vis absorption spectra of DNA-AuNP cluster conjugates with different colors. (A) UV-Vis absorption spectra of DNA-AuNP cluster conjugates. The concentration of DTT is 800 μM and the concentration of DNA (from a to e) are as follows: 2 nM, 10 nM, 100 nM, 1 μM, and 5 μM. Inset: FESEM image of DNA-AuNP clusters formed by the addition of 5 μM of DNA. (B) DNA-AuNP cluster conjugates with different colors. The concentration of DTT is 800 μM, the concentration of DNA from left to right is 10 μM, 5μM, 1μM, 100 nM, 10 nM, and 2 nM.