The focus of this article is to describe a simple-to-use, disposable sensor
suitable for the rapid determination of pollutants in aqueous media, utilising a
novel sonochemical microelectrode fabrication technique. The use of screen-
printing, electrochemical and sonochemical methods allows the production of
microelectrode arrays capable of stir-independent determination of chlorine in
water. These arrays permit the simultaneous measurement of free and total
chlorine at concentrations between 0-20 ppm. Developments leading to production
on a mass scale will be briefly discussed. A further system incorporating enzyme
containing conductive polymers to give microelectrode arrays capable of
detection of ultra-low levels of organophosphate pesticides will also be
described. Acetylcholine esterase could be entrapped within conductive
polyaniline protrusions and the effects of pesticides on its activity
determined. Ultra low concentrations of pesticide were found to reduce the
enzymes activity as measured electrochemically. These systems allow the
detection of organophosphates at concentrations as low as (10-17 M)