MALDI-TOF MS sample preparation by using alkanethiolate self-assembled monolayers: A preliminary application for protein sample analysis

Samples originating from body fluids often contain a complex mixture of inorganic salts, buffers, chaotropic agents, surfactant/detergents, preservatives, and other solubilizing agents. The presence of those contaminants often precludes direct analysis by matrix-assisted laser-desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Self-assembled monolayers (SAMs) on coinage metal can provide versatile modeling systems for studies of interfacial electron transfer, biological interactions, molecular recognition and other interfacial phenomena. In this study, SAMs surface was used for MALDI-TOF MS sample cleanup application. Experimental results from MALDI-TOF MS have revealed the better S/N ratio and resolution of using functionalized SAMs surface for the demonstration of bovine serum albumin (BSA) in artificial human urine sample. This paper reports a surface modification and cleanup method that greatly simplifies this sample preparation process.