Slide- and Micoarray-Based Biosensors Using Noble Metal Nanoparticles - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 62

change of the bulk refractive index. The detection limit (DL) for
streptavidin-biotin binding by a sensor fabricated from 39 nm
diameter AuNPs is 20-fold better than a sensor fabricated from
13 nm diameter AuNPs. 17 Moreover, Au and Ag nanoparticles
functionalized with bovine or human serum albumin and attached
to glass substrates were also used to detect the respective antibody
and a detection limit of about 10 nM was achieved. 24,25
Figure 4.4 (A) Schematic of the steps involved in the fabrication of
the immobilized colloidal gold sensor chip on glass. Glass
substrate was functionalized with APTES (1) to provide an
amine-terminated surface for formation of a monolayer of
gold nanoparticles. Self-assembled monolayer of MPA (2) on
gold nanoparticles provides a reactive carboxyl group that
can be further modiied by biotin (3) to study speciic binding
of streptavidin. (B) Biomolecular binding at the surface of
the functionalized gold monolayer results in a shift in peak
wavelength as well as an increase in intensity. Reprinted with
permission from ref. 23, Copyright 2002, American Chemical
Society.
The refractive index sensitivity (RIS) of LSPR-based sensors
in terms of wavelength-shift can be largely inluenced by the size
or shape of NMNPs. The change in the LSPR band position as a