Mass spectrometry imaging (MSI) is a comprehensive tool for the analysis of a wide range of biomolecules. The mainstream method for molecular MSI is matrix-assisted laser desorption ionization, however, the presence of a matrix results in spectral interferences and the suppression of some analyte ions. Herein we demonstrate a new matrix-free MSI technique using nanophotonic ionization based on ...

The use of femtosecond lasers in industrial, biomedical, and defense related applications during the last 15 years has necessitated a detailed understanding of pulse propagation coupled with ultrafast laser-material interactions. Current models of ultrashort pulse propagation in solids describe the pulse evolution of fields with broad spectra and are typically coupled to models of ionization an...

The use of human urine as a diagnostic tool has many advantages, such as ease of sample acquisition and noninvasiveness. However, the discovery of novel biomarkers, as well as biomarker patterns, in urine is hindered mainly by a lack of comparable datasets. To fill this gap, we assembled a new urinary fingerprint database. Here, we report the establishment of a human urinary proteomic fingerpri...

BACKGROUND Prefractionation techniques such as serum albumin depletion are useful precursors to proteomic analysis, but they may introduce preanalytical bias if the depletion is not reproducible. We examined the reproducibility of albumin immunodepletion and describe a method of QC for this process. METHODS Depletion of albumin from pooled serum, performed using IgY immunoaffinity spin column...

Urine is an extremely valuable sample type for biomarker discovery due to the non-invasive collection and the relatively low protein content, which makes detection of perturbations associated with disease easier. SELDI-TOF analysis is ideally suited for analysis of urine since the chromatographic capture mechanism can tolerate salt and urea in the urine sample that would otherwise need to be re...

The fundamental work and current knowledge on the mechanisms of matrix-assisted laser desorption ionization with pulsed infrared lasers is reviewed and discussed, with a special emphasis on the work performed in the laboratory of the authors in the recent past. The role of the different relevant irradiation parameters (laser wavelength, laser pulse duration, irradiated area and laser fluence) a...

Neutral clusters of iron oxide are created by laser ablation of iron metal and subsequent reaction of the gas phase metal atoms, ions, clusters, etc., with an O2/He mixture. The FemOn clusters are cooled in a supersonic expansion and detected and identified in a time-of-flight mass spectrometer following laser ionization at 118 nm (10.5 eV), 193 nm (6.4 eV), or 355 nm (3.53 eV) photons. With 11...

Cocrystallization between analyte and matrix is required by matrix-assisted laser desorption/ionization and can represent a significant limitation of the technique. A molecular beam expansion, mass spectrometric method has been developed to explore the possibility of using pure solvents as matrix to avoid cocrystallization. Two kinds of solvent, liquid CS2 and liquid or supercritical CO2, have ...

The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using ...

Ionization-induced injection mechanism was introduced in 2010 to reduce the laser intensity threshold for controllable electron trapping in laser wakefield accelerators (LWFA). However, usually it generates electron beams with continuous energy spectra. Subsequently, a dual-stage target separating the injection and acceleration processes was regarded as essential to achieve narrow energy-spread...