Enzymatic Biosensor Based on the ISFET and Photopolymeric Membrane for the Determinaion of Urea

Abstract

An ISFET based enzymatic biosensor was developed for the determination of urea. Immobilization of urease was accomplished by the use of liquid mixture which contained vinylpyrrolidone, oligouretane metacrylate and oligocarbonate metacrylate and which can form a polymer under the influence of ultraviolet. The biosensor has the following characteristics: the linear field of responses is in the range of 0.05 -20 mM, curve slope -38 mV/pC, and response time 5 -10 min. The increase of the temperature from 28 to 41 8C leads to 15% increase in the intensity of the response of the biosensor. The maximum response is observed at pH 6.0 -6.5. At the increase of the NaCl concentration in solution up to 300 mM the biosensor response drops off and achieves half of its initial level. NH 4 Cl causes a stronger inhibition of enzyme activity comparing to NaCl. The results obtained with the developed biosensor correlate with the data of standard calorimetric methods. The intensity of the biosensor response decreases gradually during 40 days up to 80% of the initial level. The biosensors prepared with a fresh membrane or membrane preserved during 46 days at 2 8C gave similar responses in solution with an equal concentration of a substrate. It is concluded that the developed enzymatic biosensor is perspective for its clinical application for the determination of urea in blood and that the proposed method to prepare a selective biological membrane may be in a simple way included in integral technology of the semiconductor transducer manufacturing.

Electrochemiluminescence Based Enzymatic Urea Sensor Using Nanohybrid of Isoluminol‐gold Nanoparticle‐graphene Oxide Nanoribbons

“…Urea biosensors commonly utilize the urease enzyme to hydrolyze urea into ammonia and carbon dioxide, thereby increasing the pH of the analyte solution . Common methods to measure pH change are by employing pH glass electrodes , field effect transistors , and quantum dot‐based electrochemiluminescence (ECL) detectors . ECL has become an important detection technique in analytical chemistry, because of its simplicity, rapidity, and high sensitivity .…”

Liquid photopolymerizable compositions as immobilized matrix of biosensors

“…Each chip contained two ISFETs, which were characterized by 45-48 mV/pH. Construction of the ISFETs, device for registration of their response and the main algorithm of measurement were described early [4]. The gate surface of the ISFETs was preliminary cleaned by consecutive washing: sulphuric acid, water and ethanol.…”

“…Early [1][2][3][4] we developed prototypes of the enzyme-and immune biosensors based on the ISFETs and the electrolyte insulator semiconductor (EIS) structures. Both types of biosensors are perspective for use in different fields, in particular, medicine, biotechnology and environmental monitoring.…”

Prospects of Organic Conducting Polymer Modified Electrodes: Enzymosensors

“…Rebriiev and Starodub have fabricated a urea biosensor based on ion-sensitive-field-effect transistor (ISFET) and photopolymeric membrane obtained by irradiation of a liquid mixture comprising vinyl pyrrolidone, oligo urethane methacrylate, and oligocarbonate methacrylate. This urea biosensor exhibited high sensitivity, response time [134]. Pinto and Schanze have demonstrated the application of conjugated polyelectrolytes (CPEs) based on pendent ionic sulphonate and carboxylate groups for estimation of protease activity.…”