Biology Reference
In-Depth Information
Figure 14.4.
Particle-based protocols for electrochemical detection of
DNA. These assays involve the introduction of the probe-attached onto the
magnetic particles, addition of the target/hybridization event, magnetic
removal of unwanted materials, binding of the metal, and amplified
electrochemical detection of the dissolved gold (Au) (A), silver (Ag) (B),
andcadmiumsulfide(CdS)(D)nanoparticles.Me:metaltag.Alsoshownare
solid-state stripping (C)and multitarget (E)detection protocols.
the cystic fibrosis gene that could detect single- and three-base
mismatches[29].Themodificationofgoldnanoparticleswithsingle
DNA bases was used to detect single nucleotide polymorphisms
(SNP), as described by Kerman
et al.
[30]. Phosphoramidite
chemistrywasusedtoattachthemonobasesontochitosan-modified
goldnanoparticles,whichcouldthenaccumulateintoamismatched
DNA base pairing through Watson-Crick hydrogen base pairing in
the presence of DNA polymerase I. The electrochemical oxidation
signal of the gold nanoparticles could then be used to determine
the presence of mismatch sites in a synthetic 21-base DNA probe
related to tumor necrosis factor along with all its possible mutant
combinations. Liu
et al.
[31] subsequently reported a bioelectronic
method for coding SNPs using different encoding nanocrystals.
