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Enhanced NADH Oxidation Using Polytyramine/Carbon Nanotube Modified Electrodes for Ethanol Biosensing
Author(s) -
Wilson Thomas A.,
Musameh Mustafa,
Kyratzis Ilias L.,
Zhang Jie,
Bond Alan M.,
Hearn Milton T. W.
Publication year - 2017
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201700146
Subject(s) - biosensor , overpotential , cyclic voltammetry , glassy carbon , electrode , carbon nanotube , electrocatalyst , electrochemistry , nicotinamide adenine dinucleotide , chemistry , materials science , inorganic chemistry , nuclear chemistry , analytical chemistry (journal) , nanotechnology , organic chemistry , nad+ kinase , enzyme
Abstract Polytyramine (PT) has been electro‐deposited onto multi‐walled carbon nanotube (MWCNT) modified glassy carbon (GC) electrodes via oxidation of tyramine in 0.1 M H 3 PO 4 by cycling the potential over the range of −400 mV to 1300 mV ( versus Ag/AgCl). The reactivity of the resulting chemically‐modified electrodes was characterized using cyclic voltammetry in the presence and absence of reduced nicotinamide adenine dinucleotide (NADH). The modified electrodes displayed electrochemical activity due to the formation of quinone species and were catalytically active towards NADH oxidation by lowering the oxidation peak potential by 170 mV compared to the value of the MWCNT modified electrode with a peak potential of 180±10 mV ( versus Ag/AgCl). The MWCNT/PT surface was further characterized using SEM and XPS methods, which indicated that a thin polymeric film had been formed on the electrode surface. The present work demonstrates the advantage of using PT as a platform that combines both the immobilization of alcohol dehydrogenase (ADH) and the mediation of NADH oxidation at a low overpotential essential to the design of high performance ethanol biosensors, all within an easily electropolymerizable film. The resulting biosensor displayed an ethanol sensitivity of 4.28±0.06 μA mM −1 cm −2 , a linear range between 0.1 mM and 0.5 mM and a detection limit of 10 μM.