Fabrication of Biosensors - Biosensors and Biosensor Kinetics - page 39

The authors emphasize that the development of such multi-MIP platforms would not only
extend their applications but also enhance their commercial aspects. Henry et al. (2008) have
reported their initial results for the fabrication of a heterogeneous microarray of 14 different
polymers on a single microfluidic chip. They determined the best polymers for MI by testing
their polymer microarray against the fluorescent model template dansyl- L -phenylalanine.
The fabrication of the molecularly imprinted polymer consisted of the following steps, and is
briefly described below:
(a) Derivatization of the glass substrates. The glass cover slips were cleaned by sonication
in HCl, and rinsed and sonicated in deionized water.
(b) Assembly of the microfluidic device. Microfluidic channels 300 m m wide connected to a
polymerization chamber 5 mm wide were laser cut into a silicon sheet 300 m m thick.
(c) Polymerization solutions. Fourteen monomers were used for the preparation of the poly-
mer microarray.
(d) Polymerization set-up. A CFCD camera was used to visualize and localize the polymer-
ization and the growth of the polymer dots. This procedure was repeated for each of the
different polymer compositions. The polymerization was stopped once the desired diam-
eter was obtained.
The binding assays were conducted in acetonitrile.
Henry et al. (2008) report that they have developed a new method for the fabrication of
localized polymeric solutions. Their method also permitted the real-time monitoring of the
growth of polymeric structures. They indicate that their technique helps overcome previous
limitations observed in molecularly imprinted sensor microarrays. Finally, they emphasize
that their technique should find application in HTS (high-throughput screening), chemical
and biochemical sensing, and in biocompatability studies.
3.2.4 Fabrication of an Optical Fiber Imaging Sensor Using Inkjet Printing Technology
( Carter et al., 2006 ): A pH Sensor
Carter et al. (2006) have fabricated an optical fiber imaging sensor using inkjet printing tech-
nology for pH sensing. These authors indicate that for fiber-based pH sensing an approach is
to confine the pH sensitive indicators in substrates attached to the fiber surface ( Peterson
et al., 1980; Saari and Seitz, 1982; Gehrich et al., 1986; Munkholm et al., 1986; Jordan
and Walt, 1987; Nivens et al., 1998 , 2002 ). These authors further state that the traditional
methods for fabricating fiber-based pH sensors include attachment of the substrate via
mechanical ( Peterson et al., 1980; Saari and Seitz, 1982; Gehrich et al., 1986 , dip coating
( Nivens et al., 1998, 2002 ), or photo-polymerization methods ( Munkholm et al., 1986; Jordan
and Walt, 1987 ).