title: Creatinine and urea biosensors based on a novel ammonium ion-selective copper-polyaniline nano-composite.
abstract: The use of a novel ammonium ion-specific copper-polyaniline nano-composite as transducer for hydrolase-based biosensors is proposed. In this work, a combination of creatinine deaminase and urease has been chosen as a model system to demonstrate the construction of urea and creatinine biosensors to illustrate the principle. Immobilisation of enzymes was shown to be a crucial step in the development of the biosensors; the use of glycerol and lactitol as stabilisers resulted in a significant improvement, especially in the case of the creatinine, of the operational stability of the biosensors (from few hours to at least 3 days). The developed biosensors exhibited high selectivity towards creatinine and urea. The sensitivity was found to be 85 ± 3.4 mAM(-1)cm(-2) for the creatinine biosensor and 112 ± 3.36 mAM(-1)cm(-2) for the urea biosensor, with apparent Michaelis-Menten constants (KM,app), obtained from the creatinine and urea calibration curves, of 0.163 mM for creatinine deaminase and 0.139 mM for urease, respectively. The biosensors responded linearly over the concentration range 1-125 µM, with a limit of detection of 0.5 µM and a response time of 15s. The performance of the biosensors in a real sample matrix, serum, was evaluated and a good correlation with standard spectrophotometric clinical laboratory techniques was found.
authors.affiliation: Laboratory of Biomolecular Electronics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine; Biosensors & Bioelectronics Centre, IFM, Linköping University, 58183, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Zhybak
authors.affiliation: Biosensors & Bioelectronics Centre, IFM, Linköping University, 58183, Sweden. Electronic address: valbe@ifm.liu.se.
authors.forename: V
authors.initials: V
authors.lastname: Beni
authors.affiliation: Applied Physics Division, IFM, Linköping University, Linköping, 58183, Sweden.
authors.forename: M Y
authors.initials: MY
authors.lastname: Vagin
authors.affiliation: Centre for Research in Electroanalytical Technologies, Department of Science, ITT Dublin, Tallaght, Dublin 24, Ireland.
authors.forename: E
authors.initials: E
authors.lastname: Dempsey
authors.affiliation: Biosensors & Bioelectronics Centre, IFM, Linköping University, 58183, Sweden.
authors.forename: A P F
authors.initials: AP
authors.lastname: Turner
authors.affiliation: Laboratory of Biomolecular Electronics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine. Electronic address: korpan@imbg.org.ua.
authors.forename: Y
authors.initials: Y
authors.lastname: Korpan
mesh_terms: D000619:Aminohydrolases / Q000737:chemistry; D064751:Ammonium Compounds / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D015415:Biomarkers / Q000097:blood; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D003300:Copper / Q000737:chemistry; D003404:Creatinine / Q000097:blood*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007477:Ions; D053761:Nanocomposites / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014508:Urea / Q000097:blood*; D014510:Urease / Q000737:chemistry
chemical_list: D064751:Ammonium Compounds; D000814:Aniline Compounds; D015415:Biomarkers; D007477:Ions; C416807:polyaniline; D003300:Copper; D014508:Urea; D003404:Creatinine; D014510:Urease; D000619:Aminohydrolases; C023157:creatinine deiminase
keywords: Amperometric ammonium detection; Copper polyaniline composite; Creatinine; Urea