Continuous glucose monitoring (CGM) is a vital technology for diabetes patients by providing tight glycemic control. Currently, many commercially available CGM sensors use glucose oxidase (GOD) as sensor element, but this enzyme is not able to transfer electrons directly to the electrode without oxygen or an electronic mediator. We previously reported a mutated FAD dependent glucose dehydrogenase complex (FADGDH) capable of direct electron transfer (DET) via an electron transfer subunit without involving oxygen or a mediator. In this study, we investigated the electrochemical response of DET by controlling the immobilization of DET-FADGDH using 3 types of self-assembled monolayers (SAMs) with varying lengths. With the employment of DET-FADGDH and SAM, high current densities were achieved without being affected by interfering substances such as acetaminophen and ascorbic acid. Additionally, the current generated from DET-FADGDH electrodes decreased with increasing length of SAM, suggesting that the DET ability can be affected by the distance between the enzyme and the electrode. These results indicate the feasibility of controlling the immobilization state of the enzymes on the electrode surface.

通过提供严格的血糖控制，连续血糖监测（CGM）对糖尿病患者而言是一项至关重要的技术。当前，许多可商购的CGM传感器使用葡萄糖氧化酶（GOD）作为传感器元件，但是这种酶无法在没有氧气或电子介体的情况下将电子直接转移到电极上。我们之前报道过一种突变的FAD依赖性葡萄糖脱氢酶复合物（FADGDH），能够通过电子转移亚基直接进行电子转移（DET），而无需涉及氧气或介体。在这项研究中，我们通过使用3种不同长度的自组装单层膜（SAMs）控制DET-FADGDH的固定化，研究了DET的电化学反应。借助DET-FADGDH和SAM，实现了高电流密度，而不受对乙酰氨基酚和抗坏血酸等干扰物质的影响。另外，DET-FADGDH电极产生的电流随着SAM长度的增加而降低，这表明DET能力可能受到酶与电极之间距离的影响。这些结果表明控制酶在电极表面上的固定状态的可行性。