Atomic Force Microscopy of Interfacial Protein Films

Atomic force microscopy (AFM) has been used to image interfacial films of bovine serum albumen and β-casein produced at hexadecane/water and air/water interfaces, respectively. Planar oil/water and air/water interfaces have been used to model protein films such as may form in emulsions and foams. The protein films were picked up onto mica sheets and imaged under butanol. Both systems studied yielded homogeneous flat networks which could be imaged at molecular resolution and which demonstrate the potential for using AFM to probe interfacial networks.