The present invention relates to a composition for sensor films used for
detecting chemical analytes within sensors, such as polymer-absorption
chemiresistors (i.e. conductometric sensors). The present invention
provides sensor film compositions that have greater temperature stability
and sensitivity to chemical analytes, as well as methods of making these
sensor films. Sensor film compositions according to the present invention
include a crosslinked siloxane polymer comprising a monomer having a
hydrocarbon side group with greater than or equal to two carbon atoms and
a plurality of conductive particles distributed within the polymer.
Alternate preferred embodiments distribute an oil comprising siloxane
having at least one side group with greater than or equal to two carbons
through a crosslinked siloxane polymer, wherein the oil is distributed
through a crosslinked polysiloxane copolymer. Further, conductive
particles having a N.sub.2 adsorption of between about 8 to about 25
m.sup.2/g provide enhanced sensor film performance.