Comprehensive Multiphase NMR Examination of Amino Acids Binding to the Dynamic Shell of Polystyrene Nanoparticles to Understand Environmental Hazards Associated with Nanoscale Plastic
Comprehensive Multiphase NMR Examination of Amino Acids Binding to the Dynamic Shell of Polystyrene Nanoparticles to Understand Environmental Hazards Associated with Nanoscale Plastic
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DOI：
10.1021/acsanm.2c03597
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发表时间：
2022-11
影响因子：
5.9
通讯作者：
Rajshree Ghosh Biswas;R. Soong;Daniel Schmidig;Peter de Castro;Stephan Graf;F. Busse;A. Simpson;L. Casabianca
中科院分区：
文献类型：
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作者：
Rajshree Ghosh Biswas;R. Soong;Daniel Schmidig;Peter de Castro;Stephan Graf;F. Busse;A. Simpson;L. Casabianca
塑料污染是一个日益严重的环境问题。除了对野生动物构成危害外，微米和纳米级的塑料颗粒还可以吸附污染水道中的有毒小分子，当这些塑料颗粒被动物或人类摄入时，这些小分子可能会释放出来。以前的NMR研究已经检查了表面改性的聚苯乙烯纳米颗粒和氨基酸之间的结合，作为具有各种官能团的小分子的模型。然而，这些先前的研究只能检查液相，因此集中在小分子上。在目前的研究中，我们使用全面的多相NMR（CMP-NMR）来检查小分子和聚苯乙烯纳米颗粒在所有阶段，包括液体，固体和凝胶状相。通过质子光谱编辑技术和13 C固体核磁共振实验，我们发现聚苯乙烯纳米颗粒中同时含有固体和凝胶状组分。结合的氨基酸主要存在于凝胶样相中，在真正的固相中存在非常少的氨基酸。这表明结合的氨基酸与纳米颗粒壳而不是固体样核相互作用。这些实验依赖于CMP-NMR分别观察同一样品的固体，液体和凝胶状相的能力，并证明了这种方法用于理解复杂多相系统的互补性。
Plastic pollution is a growing environmental concern. In addition to posing hazards to wildlife, micro- and nano-scale plastic particles can adsorb toxic small molecules from polluted waterways, which may be released when these plastic particles are ingested by animals or humans. Previous NMR studies have examined the binding between surface-modified polystyrene nanoparticles and amino acids as models for small molecules with a variety of functional groups. These previous studies, however, could only examine the liquid phase and therefore focused on the small molecules. In the current study, we use comprehensive multiphase NMR (CMP-NMR) to examine both the small molecules and polystyrene nanoparticles in all phases including liquid, solid, and gel-like phases. Through proton spectral editing techniques and13C solid-state NMR experiments, we find that the polystyrene nanoparticles contain both solid and gel-like fractions. The bound amino acid exists primarily in the gel-like phase, with very little amino acid existing in the true solid phase. This suggests that the bound amino acid interacts with the nanoparticle shell rather than the solid-like core. These experiments relied on the ability of CMP-NMR to separately observe the solid, liquid, and gel-like phases of the same sample and demonstrate the complementary nature of this approach for understanding complex multiphase systems.