Abstract
This chapter discusses a representative sample of the accomplishments in the study of protein and molecular assembly structure and function with the scanning tunneling microscope (STM) and atomic force microscope (AFM). The properties of the probing tip also greatly affect the image obtained with scanning probe microscope, especially the resolution. Both the STM and AFM have achieved atomic resolution while imaging the surface of solid materials in vacuum, air, and solution. The protein complex photosystem II, which is involved in the oxidation of water during photosynthesis, was studied with STM by people group. The formation of nanocrystals of the electron acceptor molecule 2-octadecylthio-1,4-benzoquinone, when prepared as Langmuir-Blodgett (LB) films on silicon, was studied by Garnaes et al. using AFM. The structure of the protein membrane obtained from the photosynthetic bacteria Rhodopseudomonas viridis was investigated by Yamada H. et al. with the LB technique and AFM.