Phase separation induced rhizobia-like Ni nanoparticles and TiO2 nanowires composite arrays for enzyme-free glucose sensor

Accurate detection of blood glucose levels is necessary to prevent diabetic complications which cause disorders of the heart, kidney, retina, and neural system. Hence, we reported a novel non-enzymatic glucose biosensing platform consisting of highly ordered rhizobia-like nickel nanoparticles/titanium oxide nanowires composite arrays (Ni NPs/TiO2 NWAs). The Ni NPs/TiO2 NWAs were fabricated via hydrothermal treatment of Ti foil in a NaOH solution, Ni ion exchange, and subsequent annealing under H2/Ar. The as-reduced Ni NPs were in-situ grown on the surface of TiO2 NWAs by the phase separation of Ni and TiO2. This novel electrode of Ni NPs/TiO2 NWAs exhibits considerable sensitivity of 50.97 μA mM−1 cm−2 and low detection limit of 0.18 μM (S/N = 3) as well as a wide linear range from 1 μM to 7 mM for glucose detection. Moreover, the electrode shows powerful reliability, distinguished stability as well as high selectivity to interfering species such as ascorbic (response about 0.33%) acid and uric acid (less than 1.5%). The promising sensing characteristics Ni NPs/TiO2 NWAs could be contributed to the decreased electron and ion transfer distance of the nano-arrays resulting from the synergetic effect rendered by the highly active Ni NPs and the steady junction between NPs and NWAs. Significantly, this paper offers a consequential guide in fabricating nanocomposites and provides a promising platform for non-enzymatic glucose biosensor.