Fig. 2. Poly (T/U) tag-dependent DNA/RNA-AuNP conjugates.

a MW-assisted heating-dry labeling of DNA-AuNP and RNA-AuNP conjugates. Photographs showing the labeling results of DNA sequences with poly (T) tag at 5′-terminal (i), 3′-terminal (ii), and in the middle region (iii). Photographs showing the labeling results of RNA sequence with poly (rU) tag at 5′-terminal (iv). An inefficient and failed labeling will lead to the AuNPs aggregation. b Photographs showing the labeling results of poly (T)-tagged DNA with different numbers of T base located at 5′-terminal, 3′-terminal and in the middle region. c Photographs showing the labeling results of poly (T₅)-tagged DNA, in which one or two T bases in T₅ were replaced by A, C, and G base. Poly (T) tags at both 5′- and 3′-terminal are evaluated. d Observation of the poly (T₁₀) dependence and role in the heating-dry labeling process.