title: Chronocoulometric determination of urea in human serum using an inkjet printed biosensor.
abstract: A biosensor for the determination of urea in human serum was fabricated using a combination of inkjet printed polyaniline nanoparticles and inkjet printed urease enzyme deposited sequentially onto screen-printed carbon paste electrodes. Chronocoulometry was used to measure the decomposition of urea via the doping of ammonium at the polyaniline-modified electrode surface at -0.3 V vs. Ag/AgCl. Ammonium could be measured in the range from 0.1 to 100 mM. Urea could be measured by the sensor in the range of 2-12 mM (r(2)=0.98). The enzyme biosensor was correlated against a spectrophotometric assay for urea in 15 normal human serum samples which yielded a correlation coefficient of 0.85. Bland-Altman plots showed that in the range of 5.8-6.6 mM urea, the developed sensor had an average positive experimental bias of 0.12 mM (<2% RSD) over the reference method.
authors.affiliation: School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Ireland.
authors.lastname: Suman
authors.forename: Emmet
authors.initials: E
authors.lastname: O'Reilly
authors.forename: Michele
authors.initials: M
authors.lastname: Kelly
authors.forename: Aoife
authors.initials: A
authors.lastname: Morrin
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Smyth
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Killard
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D001774:Blood Chemical Analysis / Q000379:methods*; D032449:Canavalia / Q000201:enzymology; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004566:Electrodes; D006801:Humans; D007281:Ink; D053758:Nanoparticles / Q000737:chemistry; D011327:Printing; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013053:Spectrophotometry; D014508:Urea / Q000097:blood*; D014510:Urease / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D000644:Quaternary Ammonium Compounds; C416807:polyaniline; D014508:Urea; D014510:Urease