Biomedical Engineering Reference
In-Depth Information
Figure 12.4
h e schematic illustration of the distribution of ef ective binding sites in
imprinted bulky materials and the nanosized, imprinted particles at er the removal of
templates is done (Redrawn with permission from [10]; Copyright ® 2007 ACS).
and the resultant imprinted sites can be accessed to target species. h e
ef ective volume of imprinted materials that can rebind target species
is [d3-(d-2x)3]. In general, the x value is very small for highly cross-
linked bulky materials, although porogens or solvents are usually used
in the imprinting process. If the imprinted materials with the same size
are prepared in the form of nanostructure with a scale of 2x nm, all of
the templates can be completely removed from the highly crosslinked
matrix, and these resultant sites are all ef ective for the binding of target
species. In the case of nanosized particles, most of the imprinted sites
are situated at the surface or in the proximity of the surface. h erefore,
the forms of imprinted materials are expected to greatly improve the
binding capacity and kinetics and site accessibility of imprinted materi-
als. Compared with the imprinted i lms and surface-imprinted materi-
als, the imprinted nanomaterials have a higher ai nity and sensitivity
to target analyte, and a more homogeneous distribution of recognition
sites. On the other hand, the low-dimensional nanostructures with
imprinted sites have very regular shapes and sizes, and the tunable l ex-
ibility of shapes and sizes. h e imprinted nanomaterials also have better
dispersibility in analyte solutions, and thus greatly reduce the resistance
of mass transfer, exhibiting a fast binding kinetics [11]. In particular,
novel nanostructure assembly technologies have achieved a wide success
in building various nanodevices [12, 13]. h e imprinted nanomaterials
with well-dei ned morphologies can feasibly be installed onto the sur-
face of devices in a required form for many applications in nanosensors
and molecular detection. h at is why several groups of researchers are
very genuinely involved in the synthesis and application of imprinted
nanomaterials.
