Carboxylated/oxidized diamond nanoparticles (nominal size 100 nm) exhibit exceptionally high affinity for proteins through both hydrophilic and hydrophobic forces. The affinity is so high that proteins in dilute solution can be easily captured by diamonds, simply separated by centrifugation, and directly analyzed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS). No preseparation of the adsorbed molecules from diamonds is required for the mass spectrometric analysis. Compared to conventional MALDI-TOF-MS, an enhancement in detection sensitivity by more than 2 orders of magnitude is achieved for dilute solution containing cytochrome c, myoglobin, and albumin because of preconcentration of the probed molecules. The lowest concentration detectable is 100 pM for a 1-mL solution. Aside from the enhanced sensitivity, the overall performance of this technique does not show any sign of deterioration for highly contaminated protein solutions, and furthermore, no significant peak broadening and band shift were observed in the mass spectra. The promise of this new method for clinical proteomics research is demonstrated with an application to human blood serum.

Glycans have diverse functions and play vital roles in many biological systems, such as influenza, vaccines, and cancer biomarkers. However, full structural identification of glycans remains challenging. The glycan structure was conventionally determined by chemical methods or NMR spectroscopy, which require a large amount of sample and are not readily applicable for glycans extracted from biological samples. Although it has high sensitivity and is widely used for structural determination of molecules, current mass spectrometry can only reveal parts of the glycan structure. Herein, the full structures of glycans, including diastereomers, the anomericity of each monosaccharide, and the linkage position of each glycosidic bond, which can be determined by using tandem mass spectrometry guided by a logically derived sequence (LODES), are shown. This new method provides de novo oligosaccharide structural identification with high sensitivity and has been applied to automatic in situ structural determination of oligosaccharides eluted by means of HPLC. It is shown that the structure of a given trisaccharide from a trisaccharide mixture and bovine milk were determined from nearly 3000 isomers by using 6–7 logically selected collision‐induced dissociation spectra. The entire procedure for mass spectrometry measurement guided by LODES can be programmed in a computer for automatic full glycan structure identification.

The structures of oligosaccharides, including the differentiation of the diastereomer and anomer of each monosaccharide and the identification of linkage positions of each glycosidic bond, can be determined by a new method: tandem mass spectrometry guided by a logically derived sequence (LODES). The entire procedure of mass spectrum measurement guided by LODES can be programmed in a computer for automatic structural identification of the oligosaccharides eluted from high‐performance liquid chromatography. More information can be found in the full paper by C.‐K. Ni et al. on page 2351 in Issue 18, 2019 (DOI: 10.1002/cbic.201900228).