Nanofluidic biosensor for the investigation of catalytic enzyme activities on the single-event level

该项目将重点放在单一酶催化活性的电子检测上。为此，将开发一种新技术，将现有基于氧化还原的检测方法的灵敏度提高数量级。这种性能的提高将通过采用基于最先进的纳米技术制造方法的新型生物传感器来实现。该生物传感器将展示集成在纳米流体通道中的两个电极。在两个紧密间隔的电极之间，氧化还原活性化合物的快速氧化还原循环将允许安培检测通道活动区域内的单分子，能够电化学检测单个氧化还原活性生物分子的能力是对现有生物传感器系统的极大改进。从根本上讲，这项技术将首次允许在单粒子水平上进行生物催化的电化学研究。具体地说，我们建议监测酪氨酸酶催化氧化还原活性分子产生的实时痕迹。这将允许探索单一催化剂的动力学，并在微观水平上阐明其机理。

The project will focus on the electrical detection of the catalytic activity of single enzymes. To this end, a new technique will be developed, which will improve the sensitivity of existing redox-based detection methods by orders of magnitude. This increase in performance will be achieved by employing a novel biosensor based on state-of-the-art nanotechnology fabrication methods. The biosensor will exhibit two electrodes integrated in a nanofluidic channel. Rapid redox-cycling of a redox-active compound between the two closely spaced electrodes will permit the amperometric detection of single molecules inside the active region of the channel.The ability to electrochemically detect single redox-active biomolecules represents a great improvement to existing biosensor systems. From a fundamental point of view, the technique will, for the first time, permit electrochemical studies of biocatalysis at the single-event level. Specifically, we propose to monitor real-time traces of the production of redox-active molecules catalyzed by the enzyme tyrosinase. This will allow probing the kinetics of a single catalyst and to elucidate its mechanisms on a microscopic level.