Infrared Laser Ablation Microsampling with a Reflective Objective

Dong, C., Richardson, L.T., Solouki, T., Murray, K.K.: Infrared Laser Ablation Microsampling with a Reflective Objective. J. Am. Soc. Mass. Spectrom. 33, 463-470 (2022). doi: 10.1021/jasms.1c00306 Abstract A Schwarzschild reflective objective with a numerical aperture of 0.3 and working distance of 10 cm was used for laser ablation sampling of tissue for off-line mass spectrometry. …

Deep-ultraviolet laser ablation sampling for proteomic analysis of tissue

R.O. Lawal, L.T. Richardson, C. Dong, F. Donnarumma, T. Solouki, K.K. Murray, Deep-ultraviolet laser ablation sampling for proteomic analysis of tissue, Anal. Chim. Acta, 1184 (2021). doi: 10.1016/j.aca.2021.339021 Abstract Deep-ultraviolet laser ablation with a pulsed 193 nm ArF excimer laser was used to remove localized regions from tissue sections from which proteins were extracted for …

Multimodal Label‐Free Monitoring of Adipogenic Stem Cell Differentiation Using Endogenous Optical Biomarkers

N. Mehta, S. Shaik, A. Prasad, A. Chaichi, S.P. Sahu, Q. Liu, S.M.A. Hasan, E. Sheikh, F. Donnarumma, K.K. Murray, X. Fu, R. Devireddy, M.R. Gartia, Multimodal Label‐Free Monitoring of Adipogenic Stem Cell Differentiation Using Endogenous Optical Biomarkers, Adv. Funct. Mater., (2021) 2103955; doi: 10.1002/adfm.202103955 Abstract Stem cell-based therapies carry significant promise for treating human …

Spatially resolved analysis of Pseudomonas aeruginosa biofilm proteomes measured by laser ablation sample transfer

A.C. Pulukkody, Y.P. Yung, F. Donnarumma, K.K. Murray, R.P. Carlson, L. Hanley, Spatially resolved analysis of Pseudomonas aeruginosa biofilm proteomes measured by laser ablation sample transfer, PLoS One, 16 (2021) e0250911, doi: 10.1371/journal.pone.0250911 Abstract Heterogeneity in the distribution of nutrients and oxygen gradients during biofilm growth gives rise to changes in phenotype. There has been …

Lasers for matrix-assisted laser desorption ionization

K.K. Murray, Lasers for matrix-assisted laser desorption ionization, J. Mass Spectrom., 56 (2021) e4664. https://doi.org/10.1002/jms.4664 Abstract Matrix-assisted laser desorption ionization (MALDI) was introduced 35 years ago and has advanced from a general method for producing intact ions from large biomolecules to wide use in applications ranging from bacteria identification to tissue imaging. MALDI was enabled …

In defense of the quasimolecular ion

K.K. Murray, In defense of the quasimolecular ion, J. Mass Spectrom., 56 (2021) e4700; doi: 10.1002/jms.4700. Abstract The term quasimolecular ion has been used to describe ions comprising a molecule and weakly bound positive or negative ion or an ion formed by the loss of a proton from a molecule. This term was used in …

Label-free lipidome study of PVT of rat brain with post-traumatic stress injury by Raman imaging

A. Chaichi, S.M.A. Hasan, N. Mehta, F. Donnarumma, P. Ebenezer, K.K. Murray, J. Francis, M.R. Gartia, Label-free lipidome study of paraventricular thalamic nucleus (PVT) of rat brain with post-traumatic stress injury by Raman imaging, Analyst, 146 (2021) 170-183. Abstract Post-traumatic stress disorder (PTSD) is a widespread psychiatric injury that develops serious life-threatening symptoms like substance …

Wavelength-Dependent Tip-Enhanced Laser Ablation of Organic Dyes

F. Cao, F. Donnarumma, K.K. Murray, Wavelength-Dependent Tip-Enhanced Laser Ablation of Organic Dyes, Journal of Physical Chemistry C, 124 (2020) 1918-1922; doi: 10.1021/acs.jpcc.9b08081 Abstract The wavelength dependence of atomic force microscope apertureless tip-enhanced laser ablation was studied using a series of organic dyes to assess the effect of surface optical absorption. An optical parametric oscillator …

Sublimation Electrification of Organic Compounds

B. Banstola, K.K. Murray, Sublimation Electrification of Organic Compounds, J. Am. Soc. Mass. Spectrom., 31 (2020) 888-893; doi: 10.1021/jasms.9b00124. Abstract The electrification of crystalline deposits of organic compounds under high vacuum was measured and quantified. A group of compounds that produce multiply charged ions by matrix-assisted ionization were deposited on a metal plate, and the …