Towards Standards for Light Scattering Studies of Proteins Stability and Nanoparticle-Protein Interactions

Abstract

Protein-nanoparticle suspensions are nowadays widely studied for the development of medical and environmental biosensors. The complexity of interactions between nanoparticles and biological fluids, together with the increasing use of dynamic light scattering (DLS) for their characterization, support the need to develop common standards for DLS measurements and analysis, in order to enable a reliable comparison of measurement results. In this study, we use 3D cross-correlation Dynamic Light Scattering (3Dcc-DLS) for the characterization of gold nanoparticles (Au NP), with spherical and rod shape, stabilized with sodium citrate, and their interaction with bovine serum albumin (BSA). We show that for Au nanorods it is possible to distinguish the rotational and translational motion. Moreover, we monitor the interaction of Au NPs and BSA over time, in order to analyse the first step of protein corona formation. Our results show that Au nanorods interact more than Au nanospheres with BSA. From the evolution of the rotational and translational peaks we conclude that the proteins tend to bind on the long cylindrical side of the nanorods.

Modulated 3D Cross-Correlation Dynamic Light Scattering Applications for Optical Biosensing and Time-Dependent Monitoring of Nanoparticle-Biofluid Interactions

“…The values obtained from Cumulants and CORENN analysis were compared by an extrapolation to zero concentration limit by linear regression. We could show that the CORENN method provides precise values of the hydrodynamic radius for rotational and translational motion of the nanorods [9]. The obtained values for the rotational motion (as listed in Table 2) are smaller than the ones earlier obtained using the CONTIN analysis which led to R H values around 2•nm for the rotational motion and around 19 nm for the translational motion [10].…”

“…Using this method, we have recently studied nanoparticle suspensions and inks [8]. in particular time-dependent behavior, such as particle-particle interactions, protein-corona formation, or formation of agglomerates can thus directly be measured and monitored at high concentration [9,10].…”

“…In particular, the standard deviation of the noise of the cross-correlation function is estimated from the experiment and used in the algorithm to weight data points depending on their reliability as assessed by the noise estimation itself [6]. Recently, we have used the CORENN method to analyse the motion of gold nanoparticles and gold nanorods, as well as the one of model proteins (BSA) and their interaction with nanoparticles [9].…”

“…Using 3D-ccDLS measurements and the CONTIN and CORENN methods, has allowed us, to determine the rotational and translational diffusion coefficients for gold nanoparticles (spheres and rods, aspect ratios varying from 1 to 5.6), and to calculate the corresponding hydrodynamic radii [10]. A comparison of Cumulants, which are stable in the range of investigated concentrations from 5 to 16 µg/mL [9], with the CORENN analysis has recently been performed by analyzing the modes of the CORENN size distributions. The values obtained from Cumulants and CORENN analysis were compared by an extrapolation to zero concentration limit by linear regression.…”

“…Au-NP1.0 28.50 ± 0.17 24. For example, for the gold nanospheres a hydrodynamic radius of (24.2 ± 0.7) nm was found from the analysis of the mode by the CORENN method, compared to an average of 27.6 nm by the CONTIN algorithm [10] and (28.50 ± 0.16) from Cumulants [9].…”