Computational Approaches in the Design of Synthetic Receptors - Designing Receptors for the Next Generation of Biosensors - page 133

Fig. 1 Scheme of: (a) three-dimensional and (b) two-dimensional molecular imprinting (courtesy
of VTT) [ 37 ]
Molecular imprinting can be defined as the process of template-induced forma-
tion of specific recognition sites (binding or catalytic) in a material where the
template directs the positioning and orientation of the material's structural
components by a self-assembling mechanism [ 36 ] (Fig. 1 ). The material itself
could be oligomeric (a typical example is the DNA replication process), polymeric
(organic MIPs and inorganic imprinted silica gels), or two-dimensional surface
assembly (grafted monolayer).
MIPs have several advantages when compared to other synthetic receptors [ 38 ]:
1. High affinity and selectivity, which are similar to those of natural receptors
2. Very high stability, which is superior to that of natural biomolecules
3. Simplicity of their preparation and the ease of adaptation to different practical
applications
A wide range of chemical compounds have been imprinted successfully, ranging
from small molecules [ 39 - 41 ] to large proteins and cells [ 42 ]. MIPs have been
developed for a variety of applications including chromatography [ 43 , 44 ], solid-
phase extraction (SPE) [ 45 , 46 ], enzyme-like catalysis [ 47 ], sensor technology
[ 43 , 48 , 49 ], biomimetic sensors [ 50 - 52 ], and immunoassays [ 53 - 55 ]. MIPs are
robust, inexpensive, and, in many cases, possess affinity and specificity that are
suitable for industrial applications. The high specificity and stability of MIPs render
them as promising alternatives to enzymes, antibodies, and natural receptors for use
in sensor technology [ 36 , 47 ].
There have been several attempts aimed at the development of a generic
procedure for MIP preparation as mentioned below; however, the method that has
been in prime focus in recent years is computational design:
1. Rational approaches involving combinatorial methods: an array of MIPs was
prepared that could be analyzed in situ by binding assays [ 56 - 60 ]
2. Use of a virtual library of functional monomers to assign and screen against the
target template molecule [ 61 - 64 ]