Shoshi Jannatul Shahrin, Mahdy M R C, Rana Mostafizur Rahman
Department of Electrical & Computer Engineering, North South University, Bashundhara, Dhaka, Bangladesh.
Heliyon. 2024 Feb 20;10(5):e26722. doi: 10.1016/j.heliyon.2024.e26722. eCollection 2024 Mar 15.
In order to determine whether a particle is plasmonic, dielectric, or chiral, different complex processes and chemicals are applied in lab setups and pharmaceutical industries. Sorting or categorizing a particle based on distinct optical forces can be a novel technique. When a beam of light interacts with a particle, it usually pushes the particle in the direction of the light's propagation. Counterintuitively, it can also pull the particle toward the light beam or move it toward a lateral direction. As far as we know, to date, no comprehensive report exists regarding a single optical arrangement capable of inducing entirely distinct behaviors of force for three disparate types of independently placed single Rayleigh particle. This study introduces an all-optical technique aimed at effectively sorting nanoscale Rayleigh-sized objects employing a plasmonic substrate, when each distinct type of single particle is placed over the substrate independently. Unfortunately, this proposed technique does not work for the cluster or mixture of distinct particles. In our proposed configuration, a simple linearly polarized plane wave is incident onto the plasmonic substrate, thereby engendering completely different responses from three different types of nanoparticles: Gold (plasmonic), SiO (dielectric), and Chiral particles. We conducted individual tests for our setup using linearly polarized plane waves at angles of 30-degree, 45-degree, and 60-degree individually. Consistent results were obtained across all angles. In each of the three distinct setups involving the aforementioned particle, a dielectric Rayleigh particle experiences an optical pulling force, a plasmonic Rayleigh particle experiences an optical pushing force, and a chiral Rayleigh particle encounters an optical lateral force. These distinctive force behaviors manifest as a result of the intricate interplay between the material properties of the nanoparticles and the characteristics of the plane-polarized beam, encompassing aspects such as plasmonic response, chirality, and refractive index. Moreover, this technique presents an environmentally sustainable and economically viable alternative to the utilization of expensive and potentially hazardous chemicals in nanoparticle sorting processes within industrial domains.
为了确定一个粒子是等离子体、电介质还是手性粒子，实验室装置和制药行业会采用不同的复杂过程和化学物质。基于不同的光学力对粒子进行分类可能是一种新技术。当一束光与一个粒子相互作用时，它通常会沿光的传播方向推动粒子。与直觉相反的是，它也可以将粒子拉向光束或使其向横向移动。据我们所知，迄今为止，尚无关于一种能够对三种不同类型的独立放置的单个瑞利粒子产生完全不同的力行为的单一光学装置的全面报告。本研究介绍了一种全光学技术，旨在当每种不同类型的单个粒子独立放置在等离子体衬底上时，有效地对纳米级瑞利尺寸的物体进行分类。不幸的是，该技术不适用于不同粒子的团簇或混合物。在我们提出的配置中，一个简单的线偏振平面波入射到等离子体衬底上，从而使三种不同类型的纳米粒子：金（等离子体）、SiO（电介质）和手性粒子产生完全不同的响应。我们分别使用30度、45度和60度角的线偏振平面波对我们的装置进行了单独测试。在所有角度都获得了一致的结果。在涉及上述粒子的三种不同设置中的每一种中，一个电介质瑞利粒子受到光学拉力，一个等离子体瑞利粒子受到光学推力，一个手性瑞利粒子受到光学横向力。这些独特的力行为是纳米粒子的材料特性与平面偏振光束的特性之间复杂相互作用的结果，包括等离子体响应、手性和折射率等方面。此外，该技术为工业领域纳米粒子分类过程中使用昂贵且潜在危险的化学物质提供了一种环境可持续且经济可行的替代方案。
