title: Poly(methyl methacrylate) microchip device integrated with gold nanoelectrode ensemble for in-column biochemical reaction and electrochemical detection.
abstract: This paper proposes a poly(methyl methacrylate) (PMMA) based microchip with an integrated gold nanoelectrode ensemble (GNEE) and a quartet-T loading channel for in-column urea/urease reactions and electrochemical detections. The on-chip GNEE electrode is fabricated using an electrodeless deposition process on a thin polycarbonate (PC) film and bonded directly onto a PMMA substrate to carry out high-performance electrochemical detections. The in-column bio-catalytic reaction of urea/urease is successfully demonstrated utilizing a novel approach based on the different electrokinetic mobilities of urea and urease in capillary electrophoresis (CE) channel. The experimental results significantly show that the GNEE electrode provides a better detection response for the reaction product of ammonia (NH(4)(+)) than a conventional planar gold electrode. The detection results demonstrate a satisfactory determination coefficient (R(2) value) and high reproducibility with a detection limit of 14.8 and 62.8 microM while detecting standard ammonia solution and the urea/urease reaction product of NH(4)(+), respectively. These results confirm the capability of the proposed device for the high-resolution CE-electrochemical detection (CE-ED) of bioanalytical reactions.
authors: Department of Chemistry, National Sun Yat-sen University, 804 Kaohsiung, Taiwan.
authors: Kuo-Tang
authors: KT
authors: Liao
authors: Chun-Mao
authors: CM
authors: Chen
authors: Hsuan-Jung
authors: HJ
authors: Huang
authors: Che-Hsin
authors: CH
authors: Lin
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods*; D004867:Equipment Design / Q000295:instrumentation / Q000379:methods; D046208:Microchip Analytical Procedures; D008839:Microelectrodes; D049329:Nanostructures; D019904:Polymethyl Methacrylate; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D015203:Reproducibility of Results; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000378:metabolism
chemical_list: D000644:Quaternary Ammonium Compounds; D014508:Urea; D019904:Polymethyl Methacrylate; D014510:Urease