G. Jobst et al., THIN-FILM CLARK-TYPE OXYGEN SENSOR-BASED ON NOVEL POLYMER MEMBRANE SYSTEMS FOR IN-VIVO AND BIOSENSOR APPLICATIONS, Biosensors & bioelectronics, 8(3-4), 1993, pp. 123-128
A planar miniaturized Clark-type oxygen sensor based on the Ross princ
iple has been produced by means of thin-film technology. The use of a
polarizable counter electrode in a three-electrode configuration allow
s the regeneration of the cathodically consumed oxygen, resulting in a
zero-flux amperometric oxygen sensor. The platinum working and counte
r electrodes and the Ag/AgCl reference electrode were covered with a p
hotostructured hydrogel layer, forming the electrolyte compartment, an
d a photostructured hydrophobic gas-permeable membrane. This arrangeme
nt exhibits no oxygen consumption and therefore the signal of the sens
or shows almost no flow dependence. Additionally, this electrochemical
feature leads to a dynamic equilibrium of the reaction products in th
e hydrogel layer, overcoming the lifetime limitations caused by buffer
degradation in the classical Clark principle. The sensor was tested i
n buffer solutions and bovine serum, showing excellent performance and
no effects of fouling on sensor response. This device can be scaled d
own and is best suited for integration with other sensors and as a bas
ic transducer for biosensors.