Modification of silicon AFM cantilever tips with an oligo(ethylene glycol) derivative for resisting proteins and maintaining a small tip size for high-resolution imaging.

We demonstrate that silicon AFM tips can be modified by etching with 2% HF solution followed by reaction with an alpha,omega-oligo(ethylene glycol)alkene. Tips properly modified by this technique maintain a small tip size and effectively reduce the nonspecific interaction with fibrinogen and bovine serum albumin, resulting in greatly improved image resolution and contrast for high-coverage fibrinogen films.