Development of an Automatic Ultrasonic Matrix Sprayer for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Abstract

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) has emerged as a powerful tool for studying the spatial distribution of various types of molecules. Matrix deposition is a critical step for obtaining high-quality imaging data. An automatic device named SoniCoat was fabricated based on an ultrasonic nozzle driven by a pizeoelectric ceramic for matrix coating in the present study. Compared with the minihumidifier developed previously by our group for matrix deposition, SoniCoat realized automation, and the ultrasonic nozzle of this device is easy to clean and less likely to get clogged, indicating a longer life. Compared with commercial and homemade instruments such as the TM-Sprayer and electrospray matrix coating device, our newly developed device achieved a good nebulization effect without the need for high-pressure gas flow and high voltage. Matrix deposition by SoniCoat generated more homogeneous matrix crystals with diameters of about 10 μm and reduced the occurrence of molecular diffusion to a greater extent, compared with the results by TM-Sprayer. Repeatable high-spatial-resolution MS imaging data were obtained with the help of SoniCoat. Furthermore, the newly developed device can also be successfully applied for in situ derivatization.

High-Efficiency Miniaturized Ultrasonic Nebulization Sample Introduction System for Elemental Analysis of Microvolume Biological Samples by Inductively Coupled Plasma Quadrupole Mass Spectrometry

“…As shown in Figure a, the nebulization rate of MUN is almost linearly correlated with the ultrasonic power. In addition, the diffusion angle of the sprayed aerosol is increased gradually with the increasing MUN nebulization rate (Figure S4), which is similar to that reported in other work . The aerosol beam dispersion becomes more pronounced over 15° with the increase of the nebulization rate over 30 μL min –1 .…”

Revealing the In Situ Behavior of Aggregation-Induced Emission Nanoparticles and Their Biometabolic Effects via Mass Spectrometry Imaging

“…The glass slide was then transferred for vacuum drying for 20 min. For matrix coating, our homemade matrix spraying instrument SoniCoat was used and the parameters were adjusted as required . In detail, the SoniCoat was set with a flow rate of matrix solution at 10 μL min –1 , a flow rate of supply nitrogen at 0.85 L min –1 , an ultrasonic power of 0.8 W, a line spacing of 1.5 mm, a nozzle moving velocity of 1.0 mm s –1 , a nozzle height of 60 mm, and cover of three layers.…”

Systematic study of tissue section thickness for MALDI MS profiling and imaging

“…[8][9][10] Many sample preparation techniques have been reported, such as sample handing (storage, cutting, and mounting), 11 tissue treatment (washing, digestion, and derivatization), 6,12,13 and matrix application (spray coating and solvent selection). 14 In turn, tissue slice thickness is a critical factor influencing the MALDI MS signal quality and imaging quality, especially for high mass analysis. 15 The proper thickness of tissue sections has been a controversial topic.…”