Non-enzymatic nickel nanoarchitectures for the development of an impedimetric glucose sensor

ENRIQUE RODRIGUEZ CASTELLON; ROMINA CARBALLO; ANA L. RINALDI; IRENE N. REZZANO; SOBRAL, SANTIAGO

Bologna

Congreso; 69th Annual Meeting of the International Society of Electrochemistry. Electrochemistry from Knowledge to Innovation; 2018

International Society of Electrochemistry

The development of non-enzymatic glucose sensors (NEGs) has been of great interest over the last years due to their ease-of-preparation, lower costs and greater stability in comparison with the enzymatic sensors. The reduction of the sample size can be achieved by combining these systems with screen-printed electrodes (SPE). On the other hand, the use of Electrochemical Impedance Spectroscopy (EIS) as transduction principle allows the improvement of detection sensitivity. Additionally, the analytical performance is increased by the use and combination of different nanomaterials, such as nickel nanoparticles, gold nanoparticles, porphyrins and carbon nanotubes (CNT).Two sets of electrodes were prepared: SPEs were modified with gold and nickel nanoparticles [1,2] (Ni(OH)2/AuNp/SPE) and glassy carbon electrodes (GCE) were modified by the polymerization of a nickel-porphyrin film doped with CNT [3], and posterior electrodeposition of nickel nanoparticles (GCE/NiPP/CNT/NiNp). These electrodes were characterized by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The performance of both modifiers was compared by evaluating the charge transfer process through EIS analysis. Ni(OH)2/AuNp/SPE proved to be the most efficient system.The selectivity of the proposed NEG in the presence of interfering species was evaluated by cyclic voltametry (CV) and EIS. Single frequency EIS analysis was performed for the quantification of glucose in salivary samples in the concentration range of 0.1 to 2 mM. The imaginary impedance values (ZI) showed the best linear response with increasing glucose levels. A slope of 0.073 k− mM-1 was obtained when plotting 1/ZI as a function of glucose concentration. The electrochemical performance revealed a synergistic effect of gold nanoparticles in the behavior of the nickel catalyst when SPEs with and without gold nanoparticles were compared. Finally, impedimetric Ni(OH)2/AuNp/SPE was proposed for the quantification of glucose in non-blood samples.