Cy3-Apt emitted a strong fluorescence signal due to the change of the structural con­

formation of the Apt by a reaction between Cy3-Apt and CAP. In addition, when heavy

metals such as Hg, Ag, and Pb were added together, Apt formed a coordinate bond with

them, which induced a fluorescence switching phenomenon, resulting in the regulation of

fluorescence intensity. Through these processes, multiple biological functions (YES, PASS 0,

INH, NOT, PASS 1, and NAND) were demonstrated successfully.

Wang’s group introduced Au@Ag core-shell nanocube to a tetrahedron-structured DNA

(tsDNA) for the development of a biologic gate (Figure 17.6b) [48]. Here, a single tsDNA-

modified Au@Ag core-shell nanocube was used as a plasmonic probe to react with multiple

targets (microRNA (miRNA), endonucleases of KpnI and StuI). When the target miRNA

was hybridized with tsDNA, the plasmonic wavelength value generated in the Au@Ag

core-shell nanocube was shifted due to the structural change by double-stranded structure

FIGURE 17.6

(a) MoS2 NPs and DNA-based resistive switching device. Adapted with permission [ 47]. Copyright (2019)

Elsevier. (b) Au@Ag core-shell nanocube-based biologic gate. Adapted with permission [ 48]. Copyright (2018)

American Chemical Society. (c) Graphene-based FET. Adapted with permission [ 49]. Copyright (2020)

American Chemical Society.

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