Ion-selective field effect transistor

Hi All

Does anyone know where I can get such a device in sensor form (not a made up probe)? Google has not been my friend on this occasion.

I have come across this company http://www.micropto.com/ who can supply a small PCB with a die attached but I'm wanting something in a package (e.g. SOT223) that incorporates the membrane.

I'm also looking to use this to measure Electrical Conductivity, I believe this can be done but don't have much information on it. I have done some work on measuring EC using graphite electrodes and an approximation of a sine wave created from the DAC output of a 18F13K50 (this was part of a 3rd year design paper) but I'd like to have a look at the ISFET as part of the 4th year design paper.

Cheers, Chris