Biomedical Engineering Reference
In-Depth Information
GCE
GS
NPG
Ab
1
Ab
2
AuNPs
BSA
GS@MnO
2
Figure 11.10
Schematic illustration for the construction of the immunosensor and
measurement protocol. (Reprinted with permission from ref [63])
In another electrochemiluminescence-based immunoassay, CdTe quan-
tum dots were used as emitters, resulting in highly sensitive, reproducible
and long-term stable immunosensor for the detection of CEA [65]. In all of
these approaches, proposed ECL immunosensors possessed excellent ana-
lytical performances, which stem from the outstanding characteristics of
NPG i lm electrodes. Improved reproducibility, satisied regeneration and
selectivity have evolved great application potential in other biological assays.
Ge
at al.
[66] prepared a platform based of thionine, NPG and graphene
(TH-NPG-GN) and used it as an ef ective matrix for immobilization of
Ab1 with good stability and bioactivity. h e secondary Ab was conjugated
to a liposome in which a large amount of HRP as label was encapsulated
(Figure 11.11). h ey applied this strategy for detection of cancer antigen
15-3. Precision, stability and reproducibility of the system showed great
improvement which makes it potentially applicable in clinical analysis.
In another sandwich-type immunoassay, NPG foils immobilized on GCE
and hollow mesoporous silica microspheres were used for immobilization
of primary and secondary anti-prostate specii c antigen, respectively [67].
h e constructed immunosensor was sensitive, simple, speciic and allowed
accurate quantiication with a low detection limit of 6.00 pg mL
-1
.
In another approach, Stine and coworkers proposed a method for detec-
tion of prostate specii c antigen or CEA in which they only used one Ab
instead of two, as in a sandwich assay format [68]. h erefore, they partially
sacrii ced high specii city of sandwich assay to preserve the low cost and
simplicity of the immunoassay. In that study, alkaline phosphatase-conju-
gated monoclonal anti-PSA or anti-CEA was immobilized on lipoic acid
