Highly sensitive quartz crystal immunosensors for multisample detection of herbicides

A piezoelectric quartz crystal immunosensor was developed for the multisample detection of herbicides in water. The antibodies against triazine derivatives were deposited onto a polystyrene-coated 9 MHz AT-cut quartz crystal resonator. A competitive immuno-reaction method with a protein-labelled antigen was utilized. The resulting frequency change due to the adsorption of protein-labelled atrazine was measured. The atrazine concentration was detectable in the range 0.001 to 1 ng/ml, and the linear correlation could be obtained from 0.01 to 1 ng/ml of atrazine. Several triazine derivatives were tested and found to be detectable owing to the cross-reactivity of the antibody.