Functional short-chain zwitterion coated silica nanoparticles with antifouling property in protein solutions

A new functional nanoparticle, consisting of a silica core onto which short-chain zwitterions are chemically connected, was successfully prepared and showed excellent antifouling performance to protein solutions. These nanoparticles (NPs) own excellent stability even in 1M NaCl solutions for at least 48 h. The interaction between these "zwitterated" NPs and proteins were investigated by dynamic light scattering (DLS), turbidimetric titration, and isothermal titration calorimetry (ITC). The results demonstrated that the zwitterated NPs had antifouling property both in single protein solutions and serum (fetal bovine serum, FBS). The zwitterated NPs also own abundant functional groups which could conjugate with biomolecules for future applications in therapeutic and diagnostic field.