title: An amperometric urea biosensor based on covalent immobilization of urease onto an electrochemically prepared copolymer poly (N-3-aminopropyl pyrrole-co-pyrrole) film.
abstract: An amperometric biosensor has been developed for the quantitative determination of urea in aqueous solution. The principle is based on the use of pH-sensitive redox active dissolved hematein molecule. The enzyme, urease (Urs), was covalently immobilized on a conducting copolymer poly (N-3-aminopropyl pyrrole-co-pyrrole) film, electrochemically prepared onto an indium-tin-oxide (ITO)-coated glass plate. The covalent linkage of enzyme and porous morphology of the polymer film lead to high enzyme loading and an increased lifetime stability of the enzyme electrode. Amperometric response was measured as a function of concentration of urea, at fixed bias voltage of 0.0 V vs. Ag/AgCl in a phosphate buffer (pH 7.0). The electrode gives a linear response range of 0.16-5.02 mM for urea in aqueous medium. The response time is 40 s reaching to a 95% steady-state current value, and 80% of the enzyme activity is retained for about 2 months.
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan. rajesh_csir@yahoo.com
authors.lastname: Rajesh
authors.forename: Vandana
authors.initials: V
authors.lastname: Bisht
authors.forename: Wataru
authors.initials: W
authors.lastname: Takashima
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kaneto
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000032:analysis / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding; D011758:Pyrroles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D014508:Urea / Q000032:analysis* / Q000737:chemistry; D014510:Urease / Q000032:analysis* / Q000737:chemistry*; D014867:Water / Q000032:analysis / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D011108:Polymers; D011758:Pyrroles; D012996:Solutions; C501276:poly (N-3-aminopropyl pyrrole-co-pyrrole); D014867:Water; D014508:Urea; D014510:Urease