Page 513 - Book Hosokawa Nanoparticle Technology Handbook

17 ADDRESSING OF NANOPARTICLES BY USING DNA MOLECULES APPLICATIONS

a b c

d e Illustration A trapped DNA
e

d Trajectory of a
free DNA
5μm
c b a
Figure 16.6
Sequential photographs of trapped and free T4 phage DNA molecules in the globule state at t 0 (a), 0.24 s (b), 0.64 s
(c), 0.87 s (d), and 1.14 s (e). Scale bar 5 m. The position of the focal point is indicated by white arrows. At t 0, the
microscope stage started to move leftward until t 0.64 s and the free DNA molecules moved with the stage. During the
motion, the optically trapped DNA molecule remained stationary. (f) The trajectories of the free and the trapped DNA
molecules are illustrated schematically.
References [3] S. Katsura, A. Yamaguchi, K. Hirano, Y. Matsuzawa
and A. Mizuno: Electrophoresis, 21, 171–175
[1] K. Yoshikawa, Y. Matsuzawa: J. Am. Chem. Soc., 118,
(2000).
929–930 (1996).
[4] S. Katsura, K. Hirano, Y. Matsuzawa, K. Yoshikawa
[2] J. Komatsu, M. Nakano, H. Kurita, K. Takashima,
and A. Mizuno: Nucleic Acids Res., 26, 4943–4945
S. Katsura and A. Mizuno: Electrophoresis, 26,
(1998).
4296–4303 (2005).
APPLICATION 17
17 ADDRESSING OF NANOPARTICLES BY USING DNA MOLECULES

DNA serves as the stores of genetic information, Specific hydrogen bonds are formed between bases
which are expressed as a sequence of four bases – of each strand (Fig. 17.2). ‘A’ specifically links only
adenine (A) thymine (T), guanine (G) and cytosine ‘T’, and ‘G’ specifically links only ‘C’. The hydrogen
(C). The structure of DNA is a double helix form of bonds can be destabilized by alkaline treatment or
2 nm in diameter as shown in Fig. 17.1. heat treatment, and double-stranded DNA (dsDNA) is
converted into single-stranded DNA (ssDNA). When
denatured ssDNA is restored in normal condition,
C G G G T T G G G G G G specific hydrogen bonds are formed between two
G
C
A A A A A A complementary DNA strands. This formation of the
G G C C C C C T T T A A A A T T A A C C C C
G G A A C C 2nm hydrogen bonds is called ‘hybridization’.
G G G G T T
T T Hybridization has been widely applied for detection
C C T T T T C C C C A T T of DNA molecules having same sequence by labeling
A
small DNA of known sequence (probe) by radioiso-
tope or fluorescent dye.
3.4nm
Recently it was proposed that hybridization
Figure 17.1 technique can be applied for addressing nanoparti-
Tertiary structure of DNA. cles. The energy band is affected by quantum effects
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