Richard W VachetVanderpuije, Benjamin P. K. N. Y2024-04-262024-04-2620072007-0510.7275/300396https://hdl.handle.net/20.500.14394/45306We have developed a straight forward method that uses monolayer protected clusters (MPCs) and mixed monolayer protected clusters (MMPCs) as selective extraction and concentration probes for peptides. After extraction with these nanoparticles (NPs), the peptides are analyzed by MALDI-TOF-MS to obtain their mass fingerprints. Application of the method to a test library of 146 tryptic peptides showed that cationic MPCs/MMPCs target negatively charged peptides while the anionic MPCs/MMPCs target positively charged peptides. The extraction with these NPs is also accompanied by high concentration factors such they can be used to extract and concentrate microcystin-LR at levels below the WHO guideline of 1μg/L.Analytical chemistrythesis