Determination of the two-dimensional distributions of gold nanorods by multiwavelength analytical ultracentrifugation

Abstract

Properties of nanoparticles are influenced by various parameters like size, shape or composition. Comprehensive high throughput characterization techniques are urgently needed to improve synthesis, scale up to production and make way for new applications of multidimensional particulate systems. In this study, we present a method for measuring two-dimensional size distributions of plasmonic nanorods in a single experiment. Analytical ultracentrifuge equipped with a multiwavelength extinction detector is used to record the optical and sedimentation properties of gold nanorods simultaneously. A combination of sedimentation and extinction properties, both depending on diameter and length of the dispersed nanorods, is used to measure two-dimensional distributions of gold nanorod samples. The length, diameter, aspect ratio, volume, surface and cross-sectional distributions can be readily obtained from these results. As the technique can be extended to other non-spherical plasmonic particles and can be used for determining relative amounts of particles of different shapes it provides complete and quantitative insights into particulate systems.

Opportunities and Challenges of Magnetic Seeded Filtration in Multidimensional Fractionation

“…This is a current field of research in separation technology [5], which is investigated by various groups, e.g. by density separation [6,7]. This work focuses on multidimensional separation by magnetic seeded filtration (MSF).…”

Multidimensional Particle Size Distributions and Their Application to Nonspherical Particle Systems in Two Dimensions

“…Nevertheless, not much knowledge about them is available in the particle technology community since only few techniques were available to measure them. With the advent of new techniques such as the analytical ultracentrifugation to measure full 2D distributions, a general framework is required of how to deal with 2D and higher dimensional distributions. In addition, important conversion schemes existed only for 1D data.…”

“…Only recently it has been shown how to characterize length and diameter distributions in one single experiment for plasmonic gold nanorods …”

Practical Aspects of Multiwavelength Analytical Ultracentrifugation

“…The complexity of the hardware has limited the implementation of the instruments to a few laboratories. The details of results that may be achieved with MWL-AUC have been described previously for a diverse array of sample types and investigative questions [5][6][7]14,28,30,[33][34][35][36]. However, previous publications documenting the performance of MWL-AUC have provided only cursory descriptions of the requirements to build and operate a complete system.…”