Quantum Dot-Fluorescence-Based Biosensing - Quantum Dots for DNA Biosensing - page 29

Fig. 3.4 A schematic representation of His 6 -peptide-linker-facilitated self-assembly of a molec-
ular beacon structure with or without the complementary DNA. Reprinted with the permission
from Ref. [ 12 ]. Copyright 2007 American Chemical Society ( a ) and the QD-MB-AuNP probe
with or without presence of the complementary viral RNA ( b ). Reproduced with permission from
Ref. [ 13 ]. Copyright 2010, Royal Society of Chemistry
between internal hybridization within the stem structure and hybridization between
the target and the loop structure [ 15 ]. Owing to such high specificity, MB has been
commercially used in PCR or reverse transcriptase PCR (RT-PCR) kit. As illustrated
above, fluorophore and quencher are tagged to each end of the MB. When the bea-
con unfolds in the presence of the complementary target sequence, the fluorescence of
fluorophore will be recovered. The amount of fluorescence at any given cycle, or fol-
lowing cycling, depends on the amount of specific product and can be easily detected