School of Laboratory Medicine, Hubei University of Chinese Medicine, 16 Huangjia Lake West Road, Wuhan 430065, China.
Department of Biochemistry, Hubei Center for Clinical Laboratory, 60 Dingziqiao Road, Wuhan 430064, China.
ACS Sens. 2023 Jul 28;8(7):2609-2617. doi: 10.1021/acssensors.3c00415. Epub 2023 Jun 25.
Local pH of the brain microenvironment is a prominent indicator for assessing health status and is closely related to many diseases; therefore, the development of effective in vivo pH methods is of great importance. This work demonstrates a dual-needle biosensor based on a solution-gate field-effect transistor (FET) for selective and sensitive monitoring of pH in cerebrospinal fluid in the central nervous system. The sensor consists of two parts: a needle FET modified with high-purity carbon nanotubes for electrical signal conduction and a needle gate modified with polyaniline for specific pH response. Based on the device's specific shape and sensing characteristics, the dual-needle sensor is sensitive to the measurement of pH in the living brain while maintaining excellent stability. The prepared dual-needle biosensor exhibits a high Nernstian response of 53.7 mV/pH over a wide pH range from 4.0 to 9.0 and excellent selectivity toward pH against other potential interfering species in the brain. Either in the case of directly injecting weak acids and bases into the rat brain or in the constructed acute acid-base poisoning model, the dual-needle biosensor can respond sensitively to the pH changes of the rat brain. This work has produced a unique dual-needle FET biosensor with high reliability and stability, which provides a new method for real-time monitoring of dynamic pH changes in the body.
脑微环境的局部 pH 值是评估健康状况的重要指标，与许多疾病密切相关；因此，开发有效的体内 pH 值检测方法非常重要。本工作展示了一种基于溶液门场效应晶体管（FET）的双针生物传感器，用于选择性和灵敏地监测中枢神经系统脑脊液中的 pH 值。该传感器由两部分组成：一部分是用高纯碳纳米管修饰的针 FET，用于电信号传导；另一部分是用聚苯胺修饰的针门，用于特定的 pH 响应。基于该器件的特殊形状和传感特性，双针传感器对活体大脑中 pH 值的测量具有很高的灵敏度，同时保持了出色的稳定性。所制备的双针生物传感器在 pH 值范围为 4.0 到 9.0 之间表现出 53.7 mV/pH 的高尼尔斯顿响应，对大脑中其他潜在干扰物质具有优异的 pH 值选择性。无论是直接将弱酸和弱碱注入大鼠脑内，还是在构建的急性酸碱中毒模型中，双针生物传感器都能对大鼠脑内的 pH 值变化做出敏感响应。这项工作制备了一种具有高可靠性和稳定性的独特双针 FET 生物传感器，为实时监测体内动态 pH 值变化提供了一种新方法。
