Sakata Toshiya, Nishitani Shoichi, Yasuoka Yusuke, Himori Shogo, Homma Kenta, Masuda Tsukuru, Akimoto Aya Mizutani, Sawada Kazuaki, Yoshida Ryo
Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Sci Rep. 2022 Feb 22;12(1):2949. doi: 10.1038/s41598-022-06964-4.
The Belousov-Zhabotinsky (BZ) self-oscillation reaction is an important chemical model to elucidate nonequilibrium chemistry in an open system. However, there are only a few studies on the electrical behavior of pH oscillation induced by the BZ reaction, although numerous studies have been carried out to investigate the mechanisms by which the BZ reaction interacts with redox reactions, which results in potential changes. Needless to say, the electrical characteristic of a self-oscillating polymer gel driven by the BZ reaction has not been clarified. On the other hand, a solution-gated ion-sensitive field-effect transistor (ISFET) has a superior ability to detect ionic charges and includes capacitive membranes on the gate electrode. In this study, we carried out the electrical monitoring of self-oscillation behaviors at the chemoelectrical interface based on the BZ reaction using ISFET sensors, focusing on the pH oscillation and the electrical dynamics of the self-oscillating polymer brush. The pH oscillation induced by the BZ reaction is not only electrically observed using the ISFET sensor, the electrical signals of which results from the interfacial potential between the solution and the gate insulator, but also visualized using a large-scale and high-density ISFET sensor. Moreover, the N-isopropylacrylamide (NIPAAm)-based self-oscillating polymer brush with Ru(bpy) as a catalyst clearly shows a periodic electrical response based on the swelling-deswelling behavior caused by the BZ reaction on the gate insulator of the ISFET sensor. Thus, the elucidation of the electrical self-oscillation behaviors induced by the BZ reaction using the ISFET sensor provides a solution to the problems of nonequilibrium chemistry.
别洛索夫-扎博京斯基（BZ）自振荡反应是阐明开放系统中非平衡化学的重要化学模型。然而，尽管已经开展了大量研究来探究BZ反应与氧化还原反应相互作用导致电位变化的机制，但关于BZ反应诱导的pH振荡的电学行为的研究却很少。不用说，由BZ反应驱动的自振荡聚合物凝胶的电学特性尚未阐明。另一方面，溶液门控离子敏感场效应晶体管（ISFET）具有卓越的检测离子电荷的能力，并且在栅电极上包含电容性膜。在本研究中，我们使用ISFET传感器对基于BZ反应的化学电界面处的自振荡行为进行了电学监测，重点关注pH振荡和自振荡聚合物刷的电动力学。由BZ反应诱导的pH振荡不仅可以使用ISFET传感器进行电学观测（其电信号源自溶液与栅极绝缘体之间的界面电位），还可以使用大规模高密度ISFET传感器进行可视化。此外，以钌（联吡啶）为催化剂的基于N-异丙基丙烯酰胺（NIPAAm）的自振荡聚合物刷在ISFET传感器的栅极绝缘体上基于BZ反应引起的溶胀-收缩行为清楚地显示出周期性电响应。因此，使用ISFET传感器阐明由BZ反应诱导的电自振荡行为为非平衡化学问题提供了解决方案。
