Biomedical Engineering Reference
In-Depth Information
V
N
Figure 25.1
(See companion CD for color insert.)
.Structure.of.an.N-V.center.in.diamond..The.carbon.atoms,.nitrogen.atom,.
and.vacancy.are.denoted.by.black.spheres,.a.dark.red.sphere,.and.a.blue.dashed.circle,.respectively.
9000
7500
6000
250
200
150
100
100 nm FND
35 nm FND
Alexa fluor 594
50
0
0
2
4
6
8 10 12 14
Time (s)
270
280
290
300
Figure 25.2
(See companion CD for color insert.)
.Typical.time.traces.of.the.luorescence.from.a.single.100.nm.FND.(green),.
a.single.35.nm.FND.(red),.and.a.single.Alexa.Fluor.546.dye.molecule.attached.to.a.single.DNA.molecule.(blue)..
No.sign.of.photobleaching.for.the.FNDs.is.detected.under.continuous.excitation.for.300.s..(Reprinted.by.permis-
sion.from.Fu,.C.-C.,.Lee,.H.-Y.,.Chen,.K.,.Lim,.T.-S.,.Wu,.H.-Y.,.Lin,.P.-K.,.Wei,.P.-K.,.Tsao,.P.-H.,.Chang,.H.-C.,.and.
Fann,. W.,. Characterization. and. application. of. single. luorescent. nanodiamonds. as. cellular. biomarkers,.
Proc.
Natl. Acad. Sci. USA
,.104,.727-732,.Copyright.2007.National.Academy.of.Sciences,.USA.)
The.center.is.characterized.by.its.distinct.ZPL.at.576.nm.(Zaitsev.2001),.which.can.be.easily.
distinguished. from. the. ZPL.=.638.nm. of. (N-V)
−
. (Table. 25.1).. Depending. on. the. particle.
size. and. surface. treatment,. the. (N-V)
0
. center. can. prevail. over. (N-V)
−
. as. ND. becomes.
smaller.than.20.nm.(Rondin.et.al..2010)..Although.the.neutral.center.has.not.been.so.well-
characterized.as.its.negatively.charged.counterpart.(primarily.because.of.the.dificulty.of.
producing.it.in.pure.form),.photochromism.between.these.two.centers.has.been.reported.
(Iakoubovskii.et.al..2000,.Gaebel.et.al..2006).
