A new strategy for NADH sensing using ionic liquid crystals-carbonnanotubes/nano-magnetite composite platform

Glassy carbon (GC) electrode is modified by stepwise manual casting of successive layers of ionic liquid crystals (ILC)/carbon nanotubes (CNTs) and magnetite nanoparticles. The composite [GC/(ILC-CNTs)/Fe3O4)] is used as a successful NADH biosensor. Molecular interaction of NADH is improved through the conductive and dense structure of ILC/CNTs. Magnetite nanoparticles act as electron-exchange antennas resulting in enhanced charge transfer at the interface, selective and sensitive oxidation of NADH. The type of ionic liquid used is key factor for sensor performance. The figures of merit for the proposed NADH sensor are: linear dynamic range of 5-700 mu mol L-1, a sensitivity of 0.0102 mu A mu mol(-1) L, a detection limit of 34.6 nmol L-1 and a limit of quantification of 0.115 mu mol L-1. The sensor showed a stable amperometric response and anti-interfering ability in presence of ascorbic acid, tryptophan, ibuprofen and morphine. (C) 2017 Elsevier B.V. All rights reserved.