Universal detectors that maintain high sensitivity as the detection volume is reduced to the subnanoliter scale can enhance the utility of miniaturized total analysis systems (μ-TAS). Here the unique scaling properties of the suspended microchannel resonator (SMR) are exploited to show universal detection in a 10 pL analysis volume with a density detection limit of ∼1 μg/cm3 (10 Hz bandwidth) and a dynamic range of 6 decades. Analytes with low UV extinction coefficients such as polyethylene glycol (PEG) 8 kDa, glucose, and glycine are measured with molar detection limits of 0.66, 13.5, and 31.6 μM, respectively. To demonstrate the potential for real-time monitoring, gel filtration chromatography was used to separate different molecular weights of PEG as the SMR acquired a chromatogram by measuring the eluate density. This work suggests that the SMR could offer a simple and sensitive universal detector for various separation systems from liquid chromatography to capillary electrophoresis. Moreover, since the SMR is itself a microfluidic channel, it can be directly integrated into μ-TAS without compromising overall performance.
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机译：通用检测器可以在检测体积减小到亚纳升以下时保持高灵敏度，从而可以提高小型化总分析系统（μ-TAS）的实用性。此处，利用悬浮微通道谐振器（SMR）的独特缩放特性来显示10 pL分析体积中的通用检测，其密度检测极限为〜1μg/ cm 3 （10 Hz带宽），并且动态范围为6年。具有低紫外线消光系数的分析物（例如8 kDa的聚乙二醇（PEG），葡萄糖和甘氨酸）的摩尔检测限分别为0.66、13.5和31.6μM。为了证明实时监测的潜力，当SMR通过测量洗脱液密度获得色谱图时，使用凝胶过滤色谱法分离了不同分子量的PEG。这项工作表明，SMR可以为从液相色谱到毛细管电泳的各种分离系统提供一种简单而灵敏的通用检测器。此外，由于SMR本身是微流体通道，因此可以直接集成到μ-TAS中，而不会影响整体性能。
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