SENSOR DEVICES

摘要

Sensor devices for examining fluid samples having, between the sample under examination and a detector, a membrane made of polyvinyl chloride in un-plasticised form. This membrane material acts as a barrier to paracetamol and sugars but is permeable to hydrogen peroxide and to oxalate, so these species can be determined after passing through the membrane. When they are not present as such in the sample, they may be formed from analytes which are sought (e.g. by enzymic action, which is especially applicable to the determination of glucose, using an oxidase enzyme). The membranes may be made by solvent casting, conveniently to a thickness of 10 to 40 (my)m, and used in electrolytic systems with a platinum anode. The membrane material can be formed into multi-layer membranes, which may incorporate layers of material to protect it or modify the permeability, or added materials for example enzymes.