POTENTIOMETRIC BIOSENSOR IN DOUBLE MATRIX MEMBRANE TECHNOLOGY

A throw-away urea sensor is described. A pH-sensitive disposable senso r constructed using double matrix membrane technology was used as a tr ansducer. Double matrix membrane technology describes a process where an ion-sensitive polymer matrix membrane is formed in the presence of an additional inert matrix for to improve the reproducibility of senso r production. In this case one-side silver-coated filter paper was use d as the inert matrix which was encapsulated by a heat sealing film. A pH-sensitive membrane was casted into this filter paper and on the su rface of this membrane a urease containing layer was deposited. The se nsor responded to between 10(-2) mol/l and 10(-4) mol/l urea, the resp onse slope was 32.7 mV/decade. The concentration range in which the se nsor responds is important for clinical analysis. The main advantages of this pH-based urea electrode include miniature size as well as simp le and low cost fabrication in a batch process.