A new sandwich sample holder is employed to examine the terahertz (THz) spectrum characteristics of an aqueous solution of bovine serum albumin (BSA) with the aim of exploring the interaction between water and BSA molecules and the effect of the BSA’s molecular vibration frequency on the THz absorption coefficient. In the frequency range of 0.1 to 2.5 THz, the spectral signal strength of the BSA aqueous solution is lower than that of the BSA solid sample; furthermore, the absorption coefficient reduces with the growth of its concentration and is always higher than the absorption coefficient of the solid BSA. The achieved results also reveal that the partial resonance absorption peaks of solution samples and solid samples are the same, signifying that a sandwich sample holder could be effectively employed to detect the BSA aqueous solution. We also utilize GaussianView6.0 software to conduct theoretical simulations on glycine small molecules and find out that their absorption coefficients in the presence of solution and solid conditions also exhibit similarities over a wide frequency range. The research results can be regarded as a solid reference for further exploring the THz absorption characteristics of protein aqueous solution.

中文翻译：

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微流控技术研究牛血清白蛋白水溶液的太赫兹吸收特性

采用新型夹层样品架检测牛血清白蛋白（BSA）水溶液的太赫兹（THz）光谱特征，旨在探讨水与BSA分子之间的相互作用以及BSA分子振动频率对牛血清白蛋白（BSA）水溶液的太赫兹（THz）光谱特性的影响。太赫兹吸收系数。在0.1~2.5 THz频率范围内，BSA水溶液的光谱信号强度低于BSA固体样品的光谱信号强度；而且，吸收系数随其浓度的增加而减小，且始终高于固体BSA的吸收系数。所得结果还表明，溶液样品和固体样品的部分共振吸收峰相同，这表明夹层样品架可以有效地用于检测BSA水溶液。我们还利用GaussianView6.0软件对甘氨酸小分子进行了理论模拟，发现它们在溶液和固体条件下的吸收系数在很宽的频率范围内也表现出相似性。研究结果可为进一步探索蛋白质水溶液的太赫兹吸收特性提供参考。