Chemistry Reference
In-Depth Information
CHAPTER 15
MOLECULAR IMPRINTING FOR
SENSOR APPLICATIONS
XIANGYANG WU and KEN D. SHIMIZU
15.1. INTRODUCTION TO SENSING PLATFORMS
Chemical sensors and biosensors are very powerful tools in modern analytical
sciences (Eggins 2002). The new demands of clinical diagnostics, environmental
analysis, food analysis, and pharmaceutical monitoring, as well as the detection of
illicit drugs, explosives, and chemical warfare agents has driven the development
of more selective, more sensitive, and lower cost chemical sensing systems. An essen-
tial component of every sensing system is a recognition platform that is able to selec-
tively bind a target analyte in the presence of competing analytes. Both synthetic and
biologically derived recognition platforms have been successfully incorporated
into molecular sensors. Synthetic recognition systems include synthetic molecular
receptors (Schrader and Hamilton 2005) and functionalized polymers (Senaratne
et al. 2005). Synthetic recognition platforms generally have the advantages of
enhanced stability and lower cost than biological systems. Biological recognition
systems include immobilized antibodies, enzymes, DNA, and aptamers. The bio-
logical recognition platforms generally display higher levels of affinity and
selectivity than their synthetic counterparts and can be more easily targeted toward
specific analytes.
This chapter will introduce the field of sensors based on molecular imprinted poly-
mers (MIPs). MIPs are highly cross-linked polymers that are formed with the pre-
sence of a template molecule (Haupt and Mosbach 2000; Wulff 2002). The
removal of the template molecule from the polymer matrix creates a binding cavity
that is complementary in size and shape to the template molecule and is lined with
appropriately positioned recognition groups (Scheme 15.1).
