Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan.
Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
Anal Chem. 2020 Oct 20;92(20):14031-14037. doi: 10.1021/acs.analchem.0c02948. Epub 2020 Sep 30.
Bicontinuous microemulsion (BME)-based hydrogel films were integrated with screen-printed electrodes (SPEs) comprising working, counter, and reference electrodes to form stand-alone, semi-solid-state electrochemical systems that do not require an outer electrolyte solution. The gel network of the BME hydrogel only exists in the microaqueous phase and retains the structure of the entire BME gel. Following gelation, a microaqueous phase with sufficient ionic strength ensured effective ionic conductivity, even in thin gel films. This enabled the electrochemical reaction to proceed using a thin gel film as an electrolyte solution. However, an intact micro-oil phase with no gel network enabled efficient extraction from an external oil solution and exhibited rapid electrochemistry that was comparable to that of a BME solution. Cyclic voltammograms of lipophilic redox species in oil using the gel-integrated SPE system demonstrated successfully in the oil itself and in the air with dropped oil onto the system.
双连续微乳液（BME）基水凝胶薄膜与包括工作电极、对电极和参比电极的丝网印刷电极（SPE）集成，形成独立的、半固态电化学系统，无需外部电解质溶液。BME 水凝胶的凝胶网络仅存在于微水相中，并保留整个 BME 凝胶的结构。凝胶化后，具有足够离子强度的微水相确保了有效的离子导电性，即使在薄凝胶薄膜中也是如此。这使得可以使用薄凝胶薄膜作为电解质溶液进行电化学反应。然而，具有完整微油相而没有凝胶网络的水凝胶能够从外部油溶液中进行有效的萃取，并表现出与 BME 溶液相当的快速电化学。使用凝胶集成 SPE 系统在油中和在空气中（将油滴到系统上）对油溶性氧化还原物种的循环伏安法进行了成功演示。
