Bovine Serum Albumin Adhesion Force Measurements Using an Atomic Force Microscopy

Abstract

In this thesis, a direct method of Atomic Force Microscopy (AFM) technique has been developed to measure the adhesion forces between BSA and two different surfaces: mica (a hydrophilic surface); and polystyrene (a hydrophobic surface); in PBS solution. We have shown possible to measure interactions between proteins and substrate surface directly without any modification to the substrate and the AFM tip; this means protein molecules can keep the natural elastic property within the force measurements. The average measured value of adhesion forces between BSA and mica is 0.036 ± 0.002 nN, and between BSA and polystyrene is 0.066 ± 0.003 nN. The polystyrene surface is more adhesive to BSA than the mica surface. This is consistent with previous research, which assessed that hydrophobic surfaces enhance protein adhesion but hydrophilic surfaces do not.