| Abstract: | Atomic force microscopy (AFM), in conjunction with colloid probe, coated colloid probe and cell probe techniques, has been used to measure directly the adhesive force between a polystyrene sphere (diameter 11 μm), protein bovine serum albumin (BSA) and a yeast cell, and two different membranes. These were polymeric ultrafiltration membranes of similar MWCO (4000 Da) but of different materials (ES 404 and XP 117, PCI Membrane Systems Ltd (UK)). The colloid probe was created by immobilising a polystyrene sphere onto a tipless V‐shaped AFM cantilever. The coated probe was made by adsorbing BSA on a 5 μm silica colloid, while immobilising a single yeast cell on such a tipless cantilever created the cell probe. Measurements were made in 10–2 M NaCl solution. It was found for polystyrene, protein and cell systems that the adhesive force at the ES 404 membrane was greater than that at the XP 117 membrane. The paper shows that the colloid probe, coated colloid probe and cell probe techniques can provide useful means of directly quantifying the adhesion of both inorganic and biological materials to membrane surfaces. |
