Immobilization of camel antibody (cAb-PSA-N7) onto Au/SAM-COOH substrates: Characterization and quantification by radiolabelling, XPS and ToF-SIMS measurements

Biosensors technologies are now aiming at detecting the target analytes such as proteins or nucleic acids at very low concentration. This depends strongly on the type of the surface, the protein and also on the employed techniques. Self assembled monolayers (SAMs) are very good candidates for these purposes. The determination of geometric arrangements of atoms, of elemental compositions and thickness of biomolecular overlayers used as thin film coatings of certain transducer substrates may typically be gained from high surface sensitivity techniques in general and XPS experiments in particular. This work is aimed at detecting immobilized Camel antibody (cAb) onto gold modified with carboxyl groups by radiolabelling and XPS. Camel antibody is used due to its very high stability and for its oriented covalent binding. This antibody is capable of recognising the prostate specific antigen (PSA) in the blood and may be used for other biomedical applications, such as Parkinson and Alzheimer diagnostics.