Strategies for the Immobilization of Bacteriophages on Gold Surfaces Monitored by Surface Plasmon Resonance and Surface Morphology

The use of bacteriophages as recognition elements for biosensing techniques has recently provoked much interest. Surface plasmon resonance, scanning electron microscopy, and atomic force microscopy were used for the real-time monitoring of the attachment of methicillin-resistant Staphylococcus aureus (MRSA) bacteriophages to gold using several immobilization methods. The MRSA bacterial capture efficiency of phage-functionalized surfaces was studied. We found that whereas the physisorption of phages to gold surfaces affects their biofunctionality, as expressed by their lysing efficiency of bacteria, phages bound via mixed self-assembled monolayers of L-cysteine and 11-mercaptoundecanoic acid permitted both the recognition and disruption of bacterial membranes. This is due to the formation of uniform islands on the gold surfaces, permitting an oriented positioning of the phages, thus better exposing their recognition proteins.