An In Situ Investigation of the Protein Corona Formation Kinetics of Single Nanomedicine Carriers by Self‐Regulated Electrochemiluminescence Microscopy

Abstract Protein coronas are present extensively at the bio‐nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real‐time monitor the entire formation, we report here a self‐regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy) 3 3+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle “cores” before and after loading drugs in nanomedicine carriers. The label‐free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy) 3 3+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio‐nano interface in drug delivery and targeted cancer treatment.