Citation:
M. Lotierzo, O. Y. F. Henry, S. Piletsky, I. Tothill, D. Cullen, M. Kania, B. Hock, A. P. F. Turner, Surface plasmon resonance sensor for domoic acid based on grafted imprinted polymer, Biosensors and Bioelectronics, Volume 20, Issue 2, Special Issue in Honour of Professor Pierre Coulet, 15 September 2004, Pages 145-152
Abstract:
A molecularly imprinted polymer (MIP) film for domoic acid (DA) was synthesised
by direct photo-grafting onto a gold chip suitable for a surface plasmon
resonance (SPR) based bioanalytical instrument system, the BIAcore 3000™. The
gold surface was first functionalised with a self-assembled monolayer of 2-
mercaptoethylamine and subsequent carbodiimide chemistry was performed for
covalent attachment of the photoinitiator, 4,4′-azobis(cyanovaleric acid). This
ensured that the formation of the MIP thin film, comprising 2-(diethylamino)
ethyl methacrylate as functional monomer and ethylene glycol dimethacrylate as
cross-linker, occurred only at the surface level. Optimisation and control over
the grafting procedure were achieved using contact angle measurements and atomic
force microscope (AFM) imaging. The surface grafting resulted in the formation
of thin and homogeneous MIP film with thickness of 40 nm. A competitive binding
assay was performed with free DA and its conjugate with horseradish peroxidase,
which was used as a refractive label. The sensor was evaluated for its
sensitivity, cross-reactivity, and robustness by using a BIAcore 3000™.
Likewise, monoclonal antibodies acting as natural receptors for the toxin were
studied with the same BIAcore system. Results of a comparison between the
artificial and natural receptors are reported. In contrast to monoclonal
antibodies, the regeneration of MIP chip did not affect its recognition
properties and continuous measurement was possible over a period of at least 2 m