Carbon Nanotubes-Based Potentiometric Bio-Sensors for Determination of Urea

Abstract

Abstract:The possibility of using disposable plastic-carbon potentiometric sensors as enzyme biosensors was examined. Urease enzyme was immobilized on poly(vinyl chloride) based H + -or NH4 + -selective membranes using cellulose acetate. This approach has resulted in a potentiometric response on changing the pH of the solution or NH4 + ion content due to an enzymatic reaction that occurs between urease and urea. Both types of potentiometric biosensors for urea were characterized by good analytical parameters as high sensitivity and fast response time.

Solid‐Contact Ion‐Selective Electrodes Paving the Way for Improved Non‐Zero Current Sensors: A Minireview

“…[25,26] It should be underlined that conducting polymers including alkylated polythiophenes can undergo redox process while they are present under the membrane, either spontaneously (oxidation by atmospheric oxygen in the presence of lipophilic anions [27,28] ) or under influence of electrochemical trigger. [29] The other group of materials that offer significant benefits as transducers in ASS-ISEs are carbon nanostructures, mainly multi-walled carbon nanotubes (MWCNTs) [30][31][32][33][34][35][36][37][38] but also other three-dimensionally ordered macroporous carbon, [39] colloidimprinted mesoporous, [40] graphene or its composites, [41][42][43] fullerenes. [44] Elimination of some drawbacks of classical systems as well as significant advantages are offered by application of composite materials, among others prepared from carbon nanostructures and conducting polymers, [45][46][47][48] e. g. poly (octylthiophene) and carbon nanotubes.…”