Monitoring Enzymatic Reactions in Real Time Using Venturi Easy Ambient Sonic-Spray Ionization Mass Spectrometry.
Monitoring Enzymatic Reactions in Real Time Using Venturi Easy Ambient Sonic-Spray Ionization Mass Spectrometry.
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DOI：
10.1021/acs.analchem.6b01246
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发表时间：
2016-06-21
影响因子：
7.4
通讯作者：
Zare RN
中科院分区：
文献类型：
--
作者：
Jansson ET;Dulay MT;Zare RN
我们开发了一种技术来监测空间受限的表面反应与质谱在环境条件下，而不需要电压或有机溶剂。浸入水溶液中的熔融二氧化硅毛细管彼此靠近并靠近官能化表面，产生了层流连接，得到的反应体积为105 μ L。该装置用注射泵操作，通过熔融石英毛细管将试剂输送到表面。将另一个熔融石英毛细管连接到文丘里简易环境声喷雾电离源，以与进料毛细管相比略高的流速对所得分析物进行采样。流入和流出的综合效应维持了一个化学微环境，其中平流输送的速率超过了扩散。我们展示了通过静电相互作用将乙酰胆碱酯酶固定在有机硅氧烷聚合物上的概念验证。乙酰胆碱酯酶水解成胆碱的乙酰胆碱进行实时监测的范围内的乙酰胆碱浓度，熔融石英毛细管的几何形状，和操作流速。正如预期的那样，随着乙酰胆碱浓度的增加，观察到更高的反应速率和转化率。
We developed a technique to monitor spatially confined surface reactions with mass spectrometry under ambient conditions, without the need for voltage or organic solvents. Fused-silica capillaries immersed in an aqueous solution, positioned in close proximity to each other and the functionalized surface, created a laminar flow junction with a resulting reaction volume of ∼5 pL. The setup was operated with a syringe pump, delivering reagents to the surface through a fused-silica capillary. The other fused-silica capillary was connected to a Venturi easy ambient sonic-spray ionization source, sampling the resulting analytes at a slightly higher flow rate compared to the feeding capillary. The combined effects of the inflow and outflow maintains a chemical microenvironment, where the rate of advective transport overcomes diffusion. We show proof-of-concept where acetylcholinesterase was immobilized on an organosiloxane polymer through electrostatic interactions. The hydrolysis of acetylcholine by acetylcholinesterase into choline was monitored in real-time for a range of acetylcholine concentrations, fused-silica capillary geometries, and operating flow rates. Higher reaction rates and conversion yields were observed with increasing acetylcholine concentrations, as would be expected.