Urea potentiometric enzymatic biosensor based on charged biopolymers and electrodeposited polyaniline

• Published in: Biosensors & bioelectronics 2011-06, Vol.26 (10), p.4139-4145
• Main Authors: Lakard, Boris, Magnin, Delphine, Deschaume, Olivier, Vanlancker, Guilhem, Glinel, Karine, Demoustier-Champagne, Sophie, Nysten, Bernard, Jonas, Alain M., Bertrand, Patrick, Yunus, Sami
• Format: Article
• Language: English
• Subjects: Aniline Compounds; Aqueous solutions; Biological and medical sciences; Biopolymers; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensing Techniques - statistics & numerical data; Biosensors; Biotechnology; Charging; Chemical Sciences; Chitosan; Conducting polymer; Electrochemical Techniques; Enzyme immobilization; Enzyme Stability; Enzymes, Immobilized; Fundamental and applied biological sciences. Psychology; General aspects; Glucans; Grafting; Humans; Immobilization techniques; Methods. Procedures. Technologies; Polyaniline; Polyanilines; Polyelectrolyte multilayers; Polysaccharides; Potentiometry; Sensitivity and Specificity; Stability; Urea - analysis; Urea - urine; Urea biosensor; Ureas; Urease; Various methods and equipments
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2011.04.009

A potentiometric biosensor based on urease was developed for the quantitative determination of urea concentration in aqueous solutions for biomedical applications. The urease was either physisorbed onto an electrodeposited polyaniline film (PANI), or immobilized on a layer-by-layer film (LbL) assembled over the PANI film, that was obtained by the alternate deposition of charged polysaccharides (carboxymethylpullulan (CMP) and chitosan (CHI)). In the latter case, the urease (Urs) enzyme was either physically adsorbed or covalently grafted to the LbL film using carbodiimide coupling reaction. Potentiometric responses of the enzymatic biosensors were measured as a function of the urea concentration in aqueous solutions (from 10 −6 to 10 −1 mol L −1 urea). Very high sensitivity and short response time were observed for the present biosensor. Moreover, a stability study showed a higher stability over time for the potentiometric response of the sensor with the enzyme-grafted LbL film, testifying for the protective nature of the polysaccharide coating and the interest of covalent grafting.