X-ray photoelectron spectroscopy characterization of self-assembled monolayers for micromechanical biosensing applications

Among the possible alternatives to microbiological techniques, small and extremely sensitive sensors called micromechanical oscillators are increasingly being used for the detection of very small masses or for stress sensing. Several types of biological bodies can be detected using micromechanical oscillators including proteins, peptides, viruses and bacteria. Therefore it is of great importance for the advancement of these detection methods to have a better understanding of the mechanisms used to attach the targeted bodies to the mechanical oscillators. In the present study, a silane-based self-assembled monolayers (SAM) are created over commercial cantilever mechanical oscillators. The fabricated SAMs are thoroughly characterized using high resolution angle-resolved XPS. A proof-of-concept experiment is conducted to study the performance of the characterized SAMs; this experiment is prepared in order to detect the interaction of the micromechanical oscillators with a protein (BSA) using a fluid cell from a BioAFM.