Tissue Engineering And Nanotheranostics

“9.61x6.69” b2815 Tissue Engineering and Nanotheranostics

Plasmonic Nanoparticles Application in Biosensor and Bioimaging 177

dimers were modified by stem­loop DNA sequence, and they

geometrically extend upon binding to the target resulting in an increase

in the energy of the hybridized bonding plasmon mode. Therefore,

fractional blue­shift related to the concentration of miR210 could be

detected.^136

5.2.2. Applications in plasmonic ruler

Plasmon ruler, like its name, is capable of determining the distance of

different interparticles by measuring their light scattering profile.

Preliminary works suggest that plasmonic rulers measure and monitor

dynamic distance changes over 1–100 nm length scale in biology.137–139

Alivisatos^9 and coworkers firstly verified that plasmon coupling could

be used to continuously monitor separations of gold–silver dimer up

to 70 nm for >3,000 s. In Ginger’s work, plasmonic rulers were

implemented by using reconfigurable DNA nanostructure, whose

length extended when the complementary strands were introduced,

and a visible blue­shift displayed in DFM reveal the nanostructure

change.^140

5.2.3. Nanostructures complex than dimer

One promising method for increasing the sensitivity of LSPR sensor

is to apply the plasmon hybridization mentioned above. The solution

to fabricate plasmon hybridization is to assemble plasmonic nanopar­

ticles into a multicomponent nanoarchitecture, dubbed nanoan­

tenna.118,141 For example, Larsson and Alivisatos fabricated

nanoantenna composed of Au plasmonic nanoparticles and Pd nano­

catalysts by using nanolithography, on the basis of which they plas­

monically studied gas­sensing and gas­phase catalysis.^142 Kinkhabwala

et al. showed a 1340­fold fluorescence enhancement for a single

molecule in a gold bowtie nanoantenna with 10 nm spacing.^143 Fan

et al. report a DNA­based bottom­up approach for constructing a

programmable nanohalo architecture that indirectly monitor solu­

tion­phase catalysis at single­particle level. Especially, the plasmonic

L–AuNPs and catalytic S–AuNPs are brought to close proximity

through DNA self­assembly. The locally enhanced electromagnetic