Flexible porous Ni(OH)2 nanopetals sandwiches for wearable non-enzyme glucose sensors

Abstract

In this work, flexible sandwich β-Ni(OH)2 nanopetals/nanoporous Ni/metallic glass (β-Ni(OH)2/NP-Ni/MG) electrodes for non-enzyme glucose sensor are fabricated by a facile two-step route, including dealloying Ni40Zr20Ti40 MG in HF solution and subsequently immersing the dealloyed sample in deionized water. The binder-free β-Ni(OH)2/NP-Ni/MG electrodes exhibit an excellent flexibility arising from the MG interlayer, which can be directly applied for glucose sensor without complex modification and assembly. The morphology, surface chemical states, and sensing performance of flexible electrodes are examined. The interwoven β-Ni(OH)2 nanopetals in-situ grown on the NP-Ni network provide large surface areas and affluent catalytic active sites, which accelerates the glucose diffusion and improves the utilization rate of active substances. Using the β-Ni(OH)2/NP-Ni/MG electrodes as non-enzymatic glucose sensor, a high sensitivity of 1.496 mA mM−1 cm−2 and a wide linear detection range up to 18 mM are achieved. Meanwhile, the present sandwich electrode shows high anti-interference ability, enhanced reproducibility, and long-term stability. The potential application of flexible β-Ni(OH)2/NP-Ni/MG electrodes as wearable electrode materials is discussed in detail. Moreover, the growth mechanism of β-Ni(OH)2 nanopetals is proposed. In summary, the β-Ni(OH)2/NP-Ni/MG electrode has a promising application prospect in wearable glucose sensor.