3.45 - Quartz Crystal Immunosensors for Multisample Detection of Herbicides

Abstract

This chapter describes the quartz crystal immunosensors for multisample detection of herbicides. In recent years, there have been an increasing number of reports on the enzyme-linked immunosorbent methods for the detection of pesticides. The advantages of immunoassays have been exploited for both sensitive quantitation of analytes and for the development of rapid, semiquantitative assays and qualitative assays. Therefore, the immunoassay technique can be applied to the screening of the pesticides, also. In addition, several researchers have intensively developed immunosensors using quartz crystal resonators modified with antibodies. In this study, a piezoelectric quartz crystal immunosensor was developed for the multisample detection of herbicide in water. The antibodies against triazine derivatives were deposited onto the polystyrene-coated 9 MHz AT-cut quartz crystal resonator. A competitive immuno-reaction method with a protein-labeled antigen was chosen because of the high sensitivity. The frequency change because of the adsorption of protein-labeled atrazine was measured. The atrazine concentration was determined in the range 0.001 to 1 ppb, and the linear correlation could be obtained from 0.01 to 1 ppb of atrazine. Several triazine derivatives were tested.