High-Throughput Colorimetric Analysis of Nanoparticle-Protein Interactions Based on the Enzyme-Mimic Properties of Nanoparticles.

While an in-depth understanding of the biological behavior of engineered nanoparticles (NPs) is of great importance for their various applications, it remains challenging to quantitatively characterize NP-protein interactions in a simple and high-throughput manner. In the present work, we propose a new, colorimetric approach capable of quantitatively analyzing the adsorption of proteins onto the surface of NPs by their distinct peroxidase-mimic properties. Taking cationic AuNPs as an example, we demonstrate that this colorimetric method is capable of evaluating NP-protein interactions in a simple and high-throughput manner in multiwell plates. Important binding parameters (e.g., the binding affinity) of three different serum proteins (bovine serum albumin, transferrin, and lysozyme) as well as human serum to AuNPs with three different sizes (average diameters of 5, 10, and 15 nm) have been obtained. Based on a quantitative analysis of NP-protein interactions, we observe that the binding affinity and the inhibition efficiency of the nanozyme activity of AuNPs are strongly affected by the characteristics of proteins as well as the sizes of NPs. These results illustrate the great potential of the present colorimetric method as a simple, low-cost, and high-throughput platform for quantitatively investigating NP-protein interactions.