Detection of staphylococcal enterotoxin B employing a piezoelectric crystal immunosensor.

This paper reports on a study concerning the development of a biochemical sensor for Staphylococcal Enterotoxin B (SEB), a substance within the bracket of biological warfare. A 20 MHz piezoelectric quartz crystal sensor device was employed in a flow injection system. The assay for SEB is based on a competition scheme using polyclonal antibodies (anti-SEB). Three parameters, i.e. the flow rate in the flow cell, the incubation time and the anti-SEB concentration, were optimized. A detection limit of 0.1 microgram/ml was obtained, whereas at concentrations of SEB of 10 micrograms/ml or higher the sensor response was completely inhibited. The results were compared with a competition enzyme linked immunosorbent assay.

Development of a surface acoustic wave gas sensor for organophosphorus nerve agents employing lanthanide compounds as the chemical interface.

The results of a study dealing with surface acoustic wave gas sensors for organophosphorus compounds such as nerve agents are described. Several lanthanum coordination compounds were applied as the chemical interface. The various sensors prepared were challenged with both the nerve agent sarin and the simulant dimethyl methylphosphonate. Many aspects were studied, such as sensitivity, selectivity, reversibility and response rate as well as the effect of temperature and structural features. Detection limits down to 0.1 ppm were found. Response rates require further improvement. Degradation phenomena were observed which in some cases yielded irreversible responses. The selectivity for organophosphorus compounds was found to be promising.