Biomedical Engineering Reference
In-Depth Information
COLOR FIGURE 3.8
Modiied.non.cross-linking.colorimetric.detection.of.nucleic.acid.targets..(A.and.B).AuNP.functionalized.with.
one.set.of.oligonucleotide.probe,.which.is.attached.to.the.AuNP.via.a.spacer.and.thiol.bond..(C).In.the.pres-
ence.of.the.complementary.target.DNA,.hybridization.occurs..(D).If.the.absence.of.complementary.target,.no.
hybridization.occurs..(E).Upon.addition.of.NaCl,.the.solution.where.hybridization.occurred.remains.red..This.is.
because.the.hybridized.oligonucleotides.increase.the.negative.charge.of.AuNPs,.thereby.increasing.their.resis-
tance.to.aggregation..(F).In.the.solution.where.no.hybridization.occurred,.addition.of.NaCl.induces.aggregation.
of.AuNPs.by.neutralizing.their.negative.charge,.and.the.solution.color.changes.from.red.to.blue.
