Shitanda Isao, Sawahara Chiaki, Loew Noya, Takasaki Yuichi, Ogura Taku, Watanabe Hikari, Itagaki Masayuki
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Langmuir. 2025 Aug 5;41(30):20382-20390. doi: 10.1021/acs.langmuir.5c02857. Epub 2025 Jul 26.
Sugars and sugar surfactants can increase the storage stability of enzyme electrodes. In this study, the feasibility of using sugar surfactants as stabilizers for enzyme electrode operation under acidic conditions was investigated along with their stabilizing mechanism. Lactate oxidase (LOx)-sucrose monolaurate-modified electrodes maintained ∼80% of their activity at pH 5.0, compared with ∼50% activity retention without a stabilizer. To elucidate the stabilizing mechanism, the structure of sucrose monolaurate with and without LOx on common electrode materials was analyzed using grazing incidence small-angle X-ray scattering (GI-SAXS). The results revealed that LOx was embedded in hexagonal arrangements and lamellar structures comprising sucrose monolaurate. Encapsulation protected the microenvironment of the enzyme against pH changes, without hindering its access to the substrate and mediator. This study confirms the high potential utility of GI-SAXS as a powerful tool for elucidating the structure-derived mechanisms of enzyme-electrode modifications.
糖类和糖表面活性剂可以提高酶电极的储存稳定性。在本研究中，研究了使用糖表面活性剂作为酸性条件下酶电极操作稳定剂的可行性及其稳定机制。与没有稳定剂时约50%的活性保留率相比，乳酸氧化酶（LOx）-蔗糖单月桂酸酯修饰电极在pH 5.0时保持了约80%的活性。为了阐明稳定机制，使用掠入射小角X射线散射（GI-SAXS）分析了在普通电极材料上有无LOx的蔗糖单月桂酸酯的结构。结果表明，LOx嵌入由蔗糖单月桂酸酯组成的六边形排列和层状结构中。包封保护了酶的微环境免受pH变化的影响，同时不妨碍其与底物和介质的接触。本研究证实了GI-SAXS作为阐明酶电极修饰结构衍生机制的强大工具具有很高的潜在实用性。
