Use of surfactant-modified cellulose acetate for a high-linearity and pH-resistant glucose electrode

Enzyme Based Amperometric Biosensors for Food Analysis

“…These approaches however are not such as yet able to be used directly in natural products, e.g., fruits, since their pH values differ significantly from the enzyme optimum. Vadgama and co-workers [11] demonstrated rapid deactivation of a glucose oxidase enzyme electrode at pH 2.4. However, by the use of specialized outer membranes it is possible to protect the enzyme from pH deactivation for sufficient time for pH independent measurement and reuse.…”

“…Chemical modifications of several polymeric membranes, such as cellulose acetate with non-anionic surfactants [9], polyvinylchloride with surfactants [10] or different plasticizers [10] have been reported to provide promising approaches for increasing selectivity of electrochemical sensors. For membrane-based electrochemical devices, various characteristics of great analytical interest such as, the retention of the mediators, co-factors, permeability of the membrane to the analyte, extension of the linearity over the environmental concentration range, and protection of fragile biomaterial from low pH inactivation, have been reported [11]. However, under the diffusion limitations of these configurations sensitivity of probes is decreasing.…”

“…Vadgama and co-workers developed a glucose oxidase electrode covered by a cellulose acetate membrane modified with Tween-80, which ensures extended linearity over the environmental concentration range of glucose in fresh fruits and also provides protection for the immobilized glucose oxidase from low pH deactivation in low-pH samples (pH < 3) such as citrus fruit [11].…”

An Enzyme Electrode for Extended Linearity Citrate Measurements Based on Modified Polymeric Membranes

“…In a previous study we had presented CA modi®ed with cationic surfactant which had performed successful pH independent ascorbate rejection, but it was noted that at high surfactant concentrations the overall permeability to ascorbate was greatly enhanced [24]. These properties allowed the possibility of such membranes to be used as organic acid permeable outer membranes with a relatively dense structure for retention of larger cofactor molecules.…”

Electrochemical Behavior and Analytical Utility of a Controlled Porosity Cellulose Acetate Film Bearing 2,6-Dichlorophenolindophenol

“…For membrane-based electrochemical devices, various characteristics of great analytical interest such as, the retention of the mediators, cofactors or activators, the permeability of the membrane to the analyte, the extension of the linearity over the environmental concentration range, and the protection of fragile biomaterial from low pH inactivation, could be achieved [17]. However, under the diffusion limitations of these con®gurations sensitivity of probes is not suf®cient.…”