Speaker
Description
Detecting megadalton matrix-assisted laser desorption/ionization (MALDI) ions with linear ion trap mass spectrometer (LIT-MS) is a technical challenge. In this talk, we employ MALDI LIT- MS to successfully analyze megadalton protein, polymer, and proteasome ions. A homebuilt linear ion trap mass spectrometer (LIT-MS) equipped with a charge sensing particle detector (CSPD) is used for high mass ion detection. We analyze high mass ions with mass-to charge (m/z) ratios ranging from 100 kTh to 2 MTh, including thyroglobulin, alpha-2-macroglobulin, immunoglobulins (e.g., IgG and IgM), polymer (200k ~ 2MTh), and 20S and 26S proteasomes. Besides, it is also very challenging for ion trap mass spectrometry to detect megadalton ions at low concentrations. By adopting high affinity carboxylated/oxidized detonation nanodiamonds (oxDNDs) to enrich IgM molecules and form antibody-nanodiamond conjugates, ~ 5 nM (5 μg/mL) concentration has successfully reached which is better than that by the other techniques.
