detected readily through variations in the light-emitting characteristics of the
polymer NWs with high signal amplification when the appropriate receptors are
linked to the surfaces of the NWs. The light-emitting P3MT material is a promising
system to study dopant-mediated DNA detection in fluorescence chain reactionenhanced PL because of the formation of doping-induced bipolaron (i.e., cationic)
states.
Figure 25 shows color CCD images and LCM PL images and spectra of an isolated
single P3MT NW with DBSA dopant in the as-prepared, p-DNA attached, and t-DNA
hybridized states. The luminescence color of the single P3MT(DBSA) NW was green
with relatively low brightness (left image of Fig. 25a). When coupled with p-DNA,
the luminescence color changed from green to red (inset of left image of Fig. 25a).
This red-shift is attributed to conformational modification of the P3MT main chains
by electrostatic interactions between the SO 3
À group of the NW and the NH 3
+ group
and the negatively charged phosphate backbone of the wrapping p-DNAs. After
hybridization with t-DNA, the luminescence intensity was enhanced considerably
Fig. 25 (a) Color CCD images of P3MT(DBSA) (left) and P3MT(DBSA)/p-DNA + t-DNA
(right) single NWs. Inset: color CCD image of a P3MT(DBSA)/p-DNA single NW. (b) 3D
LCM PL images of a P3MT(DBSA) (left top), P3MT(DBSA)/p-DNA (left bottom), and P3MT
(DBSA)/p-DNA + t-DNA single NWs (right). (c) LCM PL spectra of P3MT(DBSA), P3MT
(DBSA)/p-DNA, P3MT(DBSA)/p-DNA + t-DNA (1-mer mismatch), and P3MT(DBSA)/
p-DNA + t-DNA (perfect match) single NWs. Inset: quantum yield of P3MT(DBSA) (A),
P3MT(DBSA)/p-DNA (B), P3MT(DBSA)/p-DNA + t-DNA (1-mer mismatch) (C), and P3MT
(DBSA)/p-DNA + t-DNA (perfect match) (D) NWs. (Reproduced with permission from [139].
Copyright 2011 Royal Society of Chemistry.)
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Y.K. Hong et al.
polymer NWs with high signal amplification when the appropriate receptors are
linked to the surfaces of the NWs. The light-emitting P3MT material is a promising
system to study dopant-mediated DNA detection in fluorescence chain reactionenhanced PL because of the formation of doping-induced bipolaron (i.e., cationic)
states.
Figure 25 shows color CCD images and LCM PL images and spectra of an isolated
single P3MT NW with DBSA dopant in the as-prepared, p-DNA attached, and t-DNA
hybridized states. The luminescence color of the single P3MT(DBSA) NW was green
with relatively low brightness (left image of Fig. 25a). When coupled with p-DNA,
the luminescence color changed from green to red (inset of left image of Fig. 25a).
This red-shift is attributed to conformational modification of the P3MT main chains
by electrostatic interactions between the SO 3
À group of the NW and the NH 3
+ group
and the negatively charged phosphate backbone of the wrapping p-DNAs. After
hybridization with t-DNA, the luminescence intensity was enhanced considerably
Fig. 25 (a) Color CCD images of P3MT(DBSA) (left) and P3MT(DBSA)/p-DNA + t-DNA
(right) single NWs. Inset: color CCD image of a P3MT(DBSA)/p-DNA single NW. (b) 3D
LCM PL images of a P3MT(DBSA) (left top), P3MT(DBSA)/p-DNA (left bottom), and P3MT
(DBSA)/p-DNA + t-DNA single NWs (right). (c) LCM PL spectra of P3MT(DBSA), P3MT
(DBSA)/p-DNA, P3MT(DBSA)/p-DNA + t-DNA (1-mer mismatch), and P3MT(DBSA)/
p-DNA + t-DNA (perfect match) single NWs. Inset: quantum yield of P3MT(DBSA) (A),
P3MT(DBSA)/p-DNA (B), P3MT(DBSA)/p-DNA + t-DNA (1-mer mismatch) (C), and P3MT
(DBSA)/p-DNA + t-DNA (perfect match) (D) NWs. (Reproduced with permission from [139].
Copyright 2011 Royal Society of Chemistry.)
234
Y.K. Hong et al.