We present a MEMS-based differential scanning calorimetric (DSC) device combining highly sensitive thermoelectric sensing, on-chip self-calibration, and microfluidic regulation for thermodynamic characterization of biomolecular samples on a minimized scale. The device integrates well-defined microfluidic reaction chambers and utilizes a three-dimensional structure in which a layer of resistive microheaters and temperature sensors are precisely aligned to these chambers to provide uniform heating, in-situ temperature sensing, and convenient self-calibration. Notably, this device exploits the novel use of an antimony-bismuth (Sb-Bi) thermopile with high thermoelectric performance to significantly enhance device sensitivity and thus allow for DSC detection with minimized sample consumption. We demonstrate the utility of this MEMS DSC device by characterizing the unfolding of proteins in a minimized volume (1 μL), and at low protein concentrations approaching practically useful levels (1 mg/mL). Quantitative thermodynamic properties including the total enthalpy change (ΔH) and melting temperature (Tm) during this conformational transition are determined and found to agree with published data.
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机译：我们提出了一种基于MEMS的差分扫描量热（DSC）装置，该装置组合高敏感的热电传感，片上自校准和微流体调节，以便在最小化尺度上进行生物分子样本的热力学表征。该装置整合着定义的微流体反应室，并利用三维结构，其中电阻微热器和温度传感器精确地对准这些腔室，以提供均匀的加热，原位温度感测和方便的自校准。值得注意的是，该装置利用具有高热电性能的锑 - 铋（SB-BI）热电堆的新颖使用，以显着增强装置灵敏度，从而允许DSC检测最小化的样品消耗。我们通过表征在最小化体积（1μl）中的蛋白质的展开，并且在几乎是有用的水平（1mg / ml）的低蛋白质浓度下，通过表征蛋白质的展开来证明该MEMS DSC装置的效用。确定在该构象转变期间的总焓变化（ΔH）和熔化温度（T M ）的定量热力学性能，并发现与已发布的数据一致。
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