The interaction of different amino acids and vacuum evaporated tetraphenyl porphyrin films was investigated by using kinetic isotherms, UV-vis spectroscopy, quartz crystal microbalance and density functional theory techniques. The adsorption process was analyzed by using pseudo-first-order and pseudo-second-order models. From these results, the adsorption order changed depending on the chemical characteristics of the porphyrin film, although most of the interactions were classified as pseudo-second-order at the films interface. From absorbance measurements, red shifts on the Soret peak positions were observed for all amino acids interacting with the metal free and the ZnTPP systems, while the position of the Soret peak barely change for the CuTPP surface, except for a slight bathocromic shift for arginine. On the other hand, the broadening of the Soret peak was more important for the ZnTPP and H₂TPP surfaces, but the interaction with the CuTPP interfaces decreased the width of the peaks in all cases. In addition, a quartz crystal microbalance analysis was employed to investigate the film sensing performance during amino acid exposure. From these results, positively charged amino acids were more easily adsorbed on the films in contrast with the polar (serine) molecule. DFT calculations exhibited important deformations for H₂TPP, the out-of-plane displacement of the Zn atom for ZnTPP, and hydrogen bond interactions with the CuTPP molecule. DFT also showed high binding energies for the positively charged amino acids but low binding energies for serine in agreement with experimental data. From these results, porphyrin films could be used as selective detectors for various L-amino acid molecules.

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四苯基卟啉薄膜作为氨基酸分子的选择性检测器

采用动力学等温线、紫外-可见光谱、石英晶体微天平和密度泛函理论技术研究了不同氨基酸与真空蒸发四苯基卟啉薄膜的相互作用。采用准一级和准二级模型分析吸附过程。根据这些结果，吸附顺序根据卟啉薄膜的化学特性而变化，尽管大多数相互作用在薄膜界面被归类为准二级。从吸光度测量中，观察到与无金属和 ZnTPP 系统相互作用的所有氨基酸的 Soret 峰位置出现红移，而 CuTPP 表面的 Soret 峰位置几乎没有变化，除了精氨酸的轻微红移。另一方面，₂ TPP 表面，但与 CuTPP 界面的相互作用在所有情况下都减小了峰的宽度。此外，采用石英晶体微量天平分析来研究氨基酸暴露期间的薄膜传感性能。根据这些结果，与极性（丝氨酸）分子相比，带正电荷的氨基酸更容易吸附在薄膜上。DFT 计算显示出 H _{2的重要变形}TPP，对于 ZnTPP，Zn 原子的平面外位移，以及与 CuTPP 分子的氢键相互作用。DFT 还显示出带正电荷的氨基酸的高结合能，但与实验数据一致，丝氨酸的结合能低。根据这些结果，卟啉薄膜可用作各种 L-氨基酸分子的选择性检测器。