Immunoassay of fumonisins by a surface plasmon resonance biosensor.
A surface plasmon resonance (SPR) immunosensor is developed to determine concentrations of the mycotoxin, fumonisin B1 (FB1), in spiked samples. Polyclonal antibodies produced against FB1 are adsorbed onto a thin gold film substrate, which is coupled to a glass prism in the Kretschmann configuration. The output beam of a planar light-emitting diode is focused through the prism to excite SPR at the surface of the gold film. When a sample containing FB1 is added to a cell on the outside of the gold film, the angular profile of reflected light intensity shifts. This changes the resonance angle and the reflected beam intensity at a selected angle, both of which are proportional to the FB1 concentration. After optimization of the antibody overlayer, a detection limit of 50 ng/mL is obtained for the direct assay with an analysis time under 10 min. Multiple sample additions and large-volume sample circulation can be used with the high-affinity antibodies to achieve lower detection limits.
Mullett
W
W
Ottawa-Carleton Chemistry Institute, Department of Chemistry, Carleton University, Ontario, Canada.
Lai
E P
EP
Yeung
J M
JM
D015374:Biosensing Techniques; D002264:Carboxylic Acids / Q000032:analysis*; D037341:Fumonisins; D007118:Immunoassay / Q000379:methods*; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods*
D002264:Carboxylic Acids; D037341:Fumonisins; C056933:fumonisin B1