Dynamic light scattering nanoparticles8/15/2023 ![]() The motion and behavior, i.e., velocity and local scattering intensity, of trapped nanoparticles is characteristic of the particle properties. The potential well is the sum of all forces, and it is generated by both the optical trapping force and surface repulsion of the nanoparticle. Nanoparticles are either trapped in the evanescent field and reside in a potential well or escape the potential well via Brownian motion due to inadequate trapping force. The evanescent fields are created by the waveguide, and there are four forces operating on the field: the gradient force (trapping force), scattering force, coating force, and drag force ( Figure 1). Nanophotonic force microscopy pushes particles against a waveguide surface, optically trapping the particles by light confinement. In this work, we present one potential application of near-field light scattering-based nanophotonic force microscopy used to evaluate changes in particle surface and size by examining the self-assembly of interpolymer complexed superparamagnetic iron oxide nanoparticles (IPC-SPIOs). Due to the difficulty in predicting nanoparticle behavior in a biological environment, there is a need for newer techniques to evaluate changes at the particle surface in varied solvents. As such, changes in particle surface properties are often important in determining whether the particles are appropriate for use in various applications. Nanoparticles can be manipulated or modified to fulfill a specific, engineered purpose, partially through changing the surface chemistry or surface coating of the particle. Nanotechnology is an increasingly integral part of modern medicine, predominantly in the fields of cell labeling, gene and drug delivery, molecular imaging, and biosensors. These findings suggest that this technique is suitable for studying particle surface changes and perhaps can be used to dynamically study reaction kinetics at the particle surface. Furthermore, we found that altering the salt concentration of the suspension solution affected the velocity of particles due to the change of dielectric constant and viscosity of the solution. Therefore, we report here the use of near-field light scattering using nanophotonic force microscopy (using a NanoTweezer TM instrument, Halo Labs) to determine the changes that occurred in hydrated particle characteristics, which is accompanied by an analytical model. The local scattering intensity is correlated with the distance between the particle and waveguide, which is affected by the size of the particle (coating thickness) as well as the interactions between the particle and waveguide (related to the zeta potential of the coating). Changes in particle size and zeta potential were indirectly assessed via differences between PEG-SPIOs and IPC-SPIOs in particle velocity and scattering intensity using near-field light scattering. Here we explored the modification of the surface of poly(ethylene glycol)-coated superparamagnetic iron oxide nanoparticles (PEG-SPIOs) with the synthetic pseudotannin polygallol via interpolymer complexation (IPC). The effect of nanoparticle surface coating characteristics on colloidal stability in solution is a critical parameter in understanding the potential applications of nanoparticles, especially in biomedicine.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |