Tutorials - Surface chemistry in BioAFM

Introduction

During the last 15 years, atomic force microscopy (AFM) has found its way from material science of hard matter to the field of biology and biomolecule research. Being a surface imaging technique it sometimes has been called "unnatural" because it looks onto biomolecules adsorbed to surfaces instead of looking at molecules in solution.
The answer was published in [1 ] and [21]: "However, living systems are filled with surfaces, especially membranes, so surfaces are arguably more relevant biologically than test tubes. In fact, AFM may be a leading technique in a new field, surface biology, which will grow in this century." "[...], 'Surface Biology' may well be a new biological frontier, replacing the 'test tube biology' that has generated such a vast amount of valuable knowledge in the last century."

The 72 page review article published in 1996 by Shao [17] gives a first insight into the requirements for sample preparation in AFM:

"It is clear that the major impediment to successful AFM imaging of biological materials is sample preparation. This is a particularly difficult issue as every sample requires a unique approach. The objective with any sample is to achieve a firm adhesion to a substrate of sufficiently minimal topography that the topography of the sample is easily discriminated. This fixing to the surface is to guarantee that the probe tip does not push the sample around during imaging."