Biology Reference
In-Depth Information
Table4.1. Goldnanoparticle-basedelectrochemicalDNAbiosensorsusing
direct detection of redox markers
Modified Electrode
Detection
Detection
Analyte
Substrate
Technique
Limit
Reference
10
−
10
mol L
−
1
DNA synthetic strands
GCE
DPV (MB)
31
×
10
−
8
M32
Adenosine
AuE
CV (Ferrocene)
2.0
×
10
−
11
M28
DNA synthetic strands
AuE
DPV (ferrocene-
1.0
polythiophene)
0.5
μ
M
Cocaine
AuE
SWV (ferrocene)
33
0.6 ng mL
−
1
Cancer antigen 15-3
AuE
CV (Prussian blue)
34
DPASV (Cd
2
+
)
10
−
13
M35
×
Cauliflower mosaic
CCPE
6.5
virus gene
E. coli
O157 specific gene
SWV [Ru(NH
3
)
6
]
3
+
SPE
0.75 amol
12
(carbon)
DPV[Ru(NH
3
)
6
]
3
+
1
×
10
−
11
M
DNA synthetic strands
AuE
36
Hydrogen peroxide
AuE
Amperometry
2.0
μ
M
37
CV (ascorbic acid) 5 ng L
−
1
(0.14 pM)
Thrombin
3D-CPNE
29
DPV[Ru(NH
3
)
6
]
3
+
0.05 mg mL
−
1
DNA damage
GCE
38
AuE: gold electrode; CCPE: chitosan-entrapped carbon paste electrode; CV: cyclic voltammetry;
3D-CPNE: three-dimensional conducting polymernanorods electrodes; DPASV: differentialpulse
anodicstrippingvoltammetry;DPV:differentialpulsevoltammetry;GCE:glassycarbonelectrode;
SPE: screen-printed electrode; SWV: square wavevoltammetry.
by Brasil de Oliveira Marques
et al.
[39] for the electrochemical
biosensing of
Salmonella
sp
.
They used for the first time a double
tagging PCR strategy based on the double labeling of the amplicon
during PCR with a digoxigenin and a
-
SH set of labeled primers.
The thiolated end allowed e
cient immobilization of the amplicon
on an Au-NP-modified graphite-epoxy composite electrode, while
digoxigeninallowedtheelectrochemicaldetectionwiththeantiDIG-
HRP reporter to be performed in the femtomolerange (Fig. 4.7).
An interesting detection approach combining enzymatic elec-
trochemical detection and silver precipitation is that reported
by Mart´ınez-Paredes
et al.
[40]. They used the enzyme alkaline
phosphatase(AP)tocatalyzethedephosphorylationofthesubstrate
3-indoxyl phosphate thus producing a compound able to reduce
silver ions in solution into a metallic deposit localized where
the enzymatic label is attached. The deposited silver is then
electrochemically stripped into solution and measured by anodic
stripping voltammetry (ASV). The DNA hybridization assay was
