Slide- and Micoarray-Based Biosensors Using Noble Metal Nanoparticles - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 70

It brought a promising example of a low-cost and portable biosensor
candidate compared to the larger and more expensive commercial
instruments.

4.4 Microarray-Based LSPR Biosensors

In the development of multiplexed sensing and high throughput
LSPR assays, Nath and Chilkoti 23 irst demonstrated that the
colorimetric LSPR sensor can be performed in an array format for
end-point assays by using a low-cost optical scanner. As shown in
Fig. 4.10, the color difference between the four sensor chips could be
discerned visually and was quantitatively conirmed by conversion
of the images to gray scale and calculation of the average intensity.

Figure 4.10 (A) Scanned images of AuNPs on glass functionalized with
APTES (1), after formation of MPA monolayer (2), and after
30 min incubation with 10 (3), and 1000 μg/mL (4) ibrinogen.
(B) Histogram of the average intensity of each chip. Error bar
represents standard deviation of the intensity distribution of
each chip. Reprinted with permission from ref. 23, Copyright
2002, American Chemical Society. See also Color Insert.

The gold-capped nanoparticle layer substrates have also been
used to develop a multiarray LSPR-based nanochip (see Fig. 4.7)
composed of 300 sensing spots, for the label-free detection of
antigen-antibody reactions. 69 Antibodies were immobilized onto