FisMat2017 - Submission - View

Abstract's title: Low-cost and controlled synthesis of Ni nanofoam for non-enzymatic glucose sensing
Submitting author: Mario Urso
Affiliation: MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania
Affiliation Address: Via S. Sofia 64, 95123 Catania
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Elena Bruno (MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy), Graziella Malandrino (Dipartimento di Scienze Chimiche, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy), Salvo Mirabella (MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy), Francesco Priolo (MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy)
Abstract

Non-enzymatic glucose sensing is based on the direct catalytic oxidation of glucose and typically allows very high sensitivity at the expense of high fabrication cost, low selectivity and poor stability. Here we report on a novel Ni nanostructure fabricated by low-cost methods and successfully applied for non-enzymatic glucose sensing [1]. A Ni nanofoam (Ni NF) with surface area of 25 m2/g is obtained by chemical bath deposition (CBD) followed by 350°C annealing in reducing ambient. The Ni NF film is made by an ensemble of Ni nanoparticles (20-30 nm in size) and exhibits an open nanoporous structure with a very high surface-to-volume ratio, which make it a promising material for sensing applications. Even if the CBD technique is presently attracting considerable attention due to its simplicity, low cost, low temperature and large area deposition, it still lacks of reproducibility. In this work a reliable methodology for the preparation of Ni NF by CBD with controlled shape and functionalization is presented. The growth kinetics of the Ni NF was studied by varying the deposition time and growth temperature, and modeled in terms of initial NiOOH film formation by heterogeneous nucleation on the substrate surface followed by nuclei growth and Ni(OH)2 precipitation [2]. Film morphology is also significantly affected by growth temperature, changing from a disordered structure at room temperature to a more ordered one at 50°C. To activate the Ni NF for glucose detection a catalytic layer of Ni(OH)2/NiOOH is formed onto the nanofoam by cyclic voltammetry (CV), while the metallic core ensures excellent electronic transport. Several glucose sensor electrodes, on flexible (ITO covered UPILEX) and on rigid substrates (ITO, FTO and Ni foam), were fabricated, showing sensitivity up to 3 mA/cm2mM, linear range of 0.01–0.7 mM, limit of detection (LOD) of 5 mM, resistance to chloride poisoning, excellent long-term stability (4% decrease in sensitivity after 64 days) and selectivity in the presence of common interfering species. Thanks to the careful investigation of Ni NF synthesis by CBD it was possible to obtain glucose sensitivity as high as 15 mA/cm2mM by adjusting the deposition time, growth temperature and substrate.

 

[1] K. O. Iwu et al., Sensors and Actuators B 224 (2016) 764–771.

[2] M. Urso et al., submitted.