Nanomaterials have been widely used to assist laser desorption ionization of biomolecules for mass spectrometry analysis. Compared with classical matrix-assisted laser desorption ionization, strategies based on nanomaterial-assisted ionization generate a clean background, which is of great benefit for the qualitative and quantitative analysis of small biomolecules, such as therapeutic and diagn...

Laser-induced silicon microcolumn arrays (LISMA) were developed as matrix-free substrates for soft laser desorption/ionization mass spectrometry (SLDI-MS). When low-resistivity silicon wafers were irradiated in air, sulfur hexafluoride, or water environment with multiple pulses from a 3 x omega mode-locked Nd:YAG laser, columnar structures were formed on the surface. The radii of curvature of t...

The 12 half-cystines of NS1 proteins are absolutely conserved among flaviviruses, suggesting their importance to the structure and function of these proteins. In the present study, peptides from recombinant Dengue-2 virus NS1 were produced by tryptic digestion in 100% H2 O, peptic digestion in 50% H2 O, thermolytic digestion in 50% H2 O, or combinations of these digestion conditions. Peptides w...

Silicon nanostructure surface fabricated from metal-assisted etching have been demonstrated as high sensitivity matrix-free laser desorption/ionization mass spectrometry chip. The silicon nanostructure morphology was found to have direct effect to the mass spectrometry ionization efficiency. Creation of different silicon nanostructure morphologies by changing the metal thickness, etching time a...

Laser desorption/ionization from structured surfaces has been the object of recently renewed interest. Conditions in the plume of material ablated from such surfaces may differ from those of a sample which is ablated in bulk. Since recombination and secondary ion-molecule reactions in the plume play a major role in determining the types and quantities of ions observed at the detector, these dif...

Sample-matrix preparation procedures are shown to greatly influence the quality of the matrix-assisted laser desorption/ionization (MALDI) mass spectra of peptides and proteins. In particular, dramatic mass discrimination effects are observed when the matrix 4-hydroxy-alpha-cyanocinnamic acid is used for analyzing complex mixtures of peptides and proteins. The discrimination effects are found t...

BACKGROUND Image authentication is one of the challenging research areas in the multimedia technology due to the availability of image editing tools. Image hash may be used for image authentication which should be invariant to perceptually similar image and sensitive to content changes. The challenging issue in image hashing is to design a system which simultaneously provides rotation robustnes...