Chemistry Reference
In-Depth Information
Figure 15.5 Changes of the sensor capacitance on exposure to phenylalanine (Phe), glycine
(Gly), phenol, and tryptophan (Trp). Reprinted from Panasyuk et al. (1999). Copyright 1999
American Chemical Society.
developed using a similar approach for detection of phylloquinone (Andersson et al.
1988). The self-assembly technique was applied to prepare an electrochemical sensor
with a nano-TiO
2
film self-assembled on a glassy carbon electrode for selective deter-
mination of parathion (Li et al. 2006). This MIP-based sensor had a detection limit of
1.0
10
28
M
21
and was successfully applied to parathion concentrations in spiked
vegetable samples. This approach has the advantages of easy preparation and fast
senor response. This approach does not yield a three-dimensional polymer mem-
brane, which limits their selectivity and stability and has limited the application of
this approach in MIP sensors.
15.5. APPLICATION OF MIPs IN SENSING
15.5.1. General Considerations
MIPs are primarily recognition platforms and do not possess any innate signaling
properties. Thus, an important challenge in developing MIP-based chemical
sensors is interfacing the MIP with a signal transduction device or mechanism
(Scheme 15.5). The second half of this chapter will present examples of different
signal transduction mechanisms and strategies that have been successfully employed
in MIP sensors. These include competitive binding assays (Section 15.5.2), mass-
sensitive devices (Section 15.5.3), and optical (Section 15.5.4) and electrochemical
sensors (Section 15.5.5).
