Hunan Institute of Advanced Sensing and Information Technology, Xiangtan University, Hunan 411105, China.
Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics, Department of Electronics, Peking University, Beijing 100871, China.
ACS Appl Mater Interfaces. 2024 Jan 10;16(1):1351-1360. doi: 10.1021/acsami.3c17309. Epub 2023 Dec 27.
Continuous glucose monitoring (CGM), which is significant for the daily management of diabetes, requires a low-power-consumption sensor system that can track low nanomolar levels of glucose in physiological fluids, such as sweat and tears. However, traditional electrochemical methods are limited to analytes in micromolar to millimolar ranges and entail high power consumption. Carbon nanotube (CNT) film field-effect transistors (FETs) are promising for constructing extremely sensitive biosensors, but their wide applications in CGM are limited by the strong screening effect of physiological fluids and the zero charge of glucose molecules. In this study, we demonstrate a glucose aptamer-modified CNT FET biosensor to realize a highly sensitive CGM system with sub-nW power consumption by applying a suitable gate voltage. A positive gate voltage can enlarge the effective Debye screening length at the double layer to reduce the local ion population nearby and then improve the sensitivity of the FET-based biosensors by 5 times. We construct CNT FET sensors for CGM with a limit of detection of 0.5 fM, a record dynamic range up to 10, and a power consumption down to ∼100 pW. The proposed field-modulated sensing performance scheme is applicable to other aptamer-based FET biosensors for detecting neutral or less charged molecules and opens opportunities to develop facilely modulated, highly sensitive, low-power, and noninvasive CGM systems.
连续血糖监测（CGM）对糖尿病的日常管理至关重要，需要一个低功耗的传感器系统，能够跟踪生理液（如汗液和眼泪）中的低纳摩尔水平的葡萄糖。然而，传统的电化学方法仅限于分析物在微摩尔到毫摩尔范围内，并且需要高功耗。碳纳米管（CNT）薄膜场效应晶体管（FET）在构建极其灵敏的生物传感器方面具有很大的潜力，但它们在 CGM 中的广泛应用受到生理液的强烈屏蔽效应和葡萄糖分子的零电荷的限制。在本研究中，我们展示了一种葡萄糖适体修饰的 CNT FET 生物传感器，通过施加适当的栅极电压，实现了一个具有亚纳瓦功耗的高灵敏度 CGM 系统。正栅压可以增大双电层中的有效德拜屏蔽长度，减少附近的局部离子数量，从而将基于 FET 的生物传感器的灵敏度提高 5 倍。我们构建了用于 CGM 的 CNT FET 传感器，其检测限为 0.5 fM，动态范围高达 10，功耗低至约 100 pW。所提出的场调制传感性能方案适用于其他基于适体的 FET 生物传感器，用于检测中性或带较少电荷的分子，并为开发简便调制、高灵敏度、低功耗和非侵入性的 CGM 系统开辟了机会。
