Zhang Chi, Muñetón Díaz José, Muster Augustin, Abujetas Diego R, Froufe-Pérez Luis S, Scheffold Frank
Department of Physics, University of Fribourg, 1700, Fribourg, Switzerland.
Nat Commun. 2024 Feb 3;15(1):1020. doi: 10.1038/s41467-024-45162-w.
Understanding the interactions between small, submicrometer-sized colloidal particles is crucial for numerous scientific disciplines and technological applications. In this study, we employ optical tweezers as a powerful tool to investigate these interactions. We utilize a full image reconstruction technique to achieve high precision in characterizing particle pairs that enable nanometer-scale measurement of their positions. This approach captures intricate details and provides a comprehensive understanding of the spatial arrangement between particles, overcoming previous limitations in resolution. Moreover, our research demonstrates that properly accounting for optical binding forces to determine the intrinsic interaction potential is vital. We employ a discrete dipole approximation approach to calculate optical binding potentials and achieve a good agreement between the calculated and observed binding forces. We incorporate the findings from these simulations into the assessment of the intrinsic interaction potentials and validate our methodology by using short-range depletion attraction induced by micelles as an example.
理解亚微米级小胶体颗粒之间的相互作用对于众多科学学科和技术应用至关重要。在本研究中，我们采用光镊作为一种强大的工具来研究这些相互作用。我们利用全图像重建技术在表征粒子对时实现高精度，从而能够对其位置进行纳米级测量。这种方法捕捉到了复杂的细节，并提供了对粒子间空间排列的全面理解，克服了以往分辨率方面的限制。此外，我们的研究表明，正确考虑光约束力以确定内在相互作用势至关重要。我们采用离散偶极近似方法来计算光结合势，并使计算出的结合力与观测到的结合力取得了良好的一致性。我们将这些模拟结果纳入对内在相互作用势的评估中，并以胶束诱导的短程耗尽吸引力为例验证了我们的方法。
