Performances of protein array platforms prepared by soft lithography and self-assemblying monolayers-approach by using SPR, ellipsometry and MALDI-MS

Immobilization of the probe protein molecules, i.e., human serum albumin (HSA) on the patterned areas ("spots") via the MUA-SAMs over layers was studied by Surface Plasmon Resonance (SPR), ellipsometry and Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry (MALDI-MS). Mercaptoundecanoicacid (MUA) molecules were micro-contact printed to form self-assembled monolayers (SAMs) on gold coated BK7 slides. Array platforms prepared by using 10 nM HSA solution were accepted as platforms with optimal properties, and then were used for detection of the target molecules, i.e., Fab fragment of anti-human serum albumin (Fab-anti-HSA). The analytical signal (the delta (Delta) value) measured was correlated with the target concentration. It demonstrated that the target molecules could be detected with SPR at nanomolar (nM) levels. Since Fab-anti-HSA could not be separated from HSA on the spots directly with MALDI-MS, an indirect method was used to break this interaction. (C) 2019 Published by Elsevier B.V.