Quasi-aligned nanorod arrays composed of Nickel-Cobalt nanoparticles anchored on TiO2/C nanofiber arrays as free standing electrode for enzymeless glucose sensors

Nickel-based enzymeless glucose sensors have been extensively explored. However, poor conductivity and severe aggregation of nickel-base nanocomposites often reduce the performance of its practical applications. Herein, free-standing TiO2/C core-shell nanofiber arrays (TiO2/C NFAs) were fabricated directly on a titanium foil to serve as the one-dimensional (1D) conductive substrate. Nickel-cobalt binary nanoparticles were then deposited on the nanofibers to form the NiCo/TiO2/C NFAs for enzymeless glucose sensing. The NiCo/TiO2/C NFAs exhibit much improved sensitivity and excellent stability towards glucose determination, with a wide linear range from 1 mu M to 7658 mu M, and a high sensitivity of 975.3 mu A mM(-1) cm(-2). The detection limit is calculated to be 0.6 mu M (S/N = 3). The NiCo/TiO2/C NFAs also show excellent selectivity with minimal interference from the coexistent species. The superior analytical performance should be attributed to the large specific surface area of the 1D nanostructure, direct electron transfer pathway via the free standing TiO2/C NFAs, and high activity of the binary Ni-Co electrocatalyst. (C) 2019 Elsevier B.V. All rights reserved.