Characteristics of the 11-Mercaptoundecanoic Acid (11-MUA) Binding to Gold Surface as Self-Assembled Monolayer (SAM) for SPR based Biosensor

Surface plasmon resonance (SPR) is an alternative approach that has piqued the researcher's interest as a highly sensitive and potentially promising technique for rapid and real-time virus diagnosis. For SPR biosensor development, efficient immobilization of biorecognition molecules onto the sensor surface is always essential. In SPR biosensor, gold (Au) is usually preferred to be used than silver (Ag) or other metals because it has good resistance to oxidation and corrosion in different environments. However, biomolecules adsorb poorly on gold which might limits the sensitivity of a conventional SPR biosensor. Therefore, an adhesive linker layer such as self-assembled monolayer (SAM), between the metal and ligands is required to functionalize the metal film and enhance the sensitivity of the SPR based sensor. The criteria that were taken into consideration for the formation of SAM layer was discussed and, the binding of a 11-MUA thiols onto an Au/BK7 prism will be experimentally demonstrate. The sample of 11-MUA/Au/BK7 sample was subjected to Raman spectroscopy for surface characterization. The present study confirms the binding of thiols SAM into gold surfaces which is important for the development of a highly performing biosensor.