Simultaneously acquiring chemical and topographical information within asingle cell at nanoscale resolutions is vital to cellular biology,yet it remains agreat challenge due to limited lateral resolutions and detection sensitivities.H erein, the development of near-field desorption mass spectrometry for correlated chemical and topographical imaging is reported, therebyb ridging the gap between laser-based mass spectrometry (MS) methods and multimodal single-cell imaging.Using this integrated platform, an imaging resolution of 250 nm and 3D topographically reconstructed chemical single-cell imaging were achieved.T his technique offers more in-depth cellular information than micrometer-range laser-based MS imaging methods.C onsidering the simplicity and compact sizeo ft he near-field device,this techniquecan be introduced to MALDI-MS,e xpanding the multimodal abilities of MS at nanoscale resolutions.
The visualization of temporal and spatial changes in the intracellular environment has great significance for chemistry and bioscience research. Mass spectrometry imaging (MSI) plays an important role because of its unique advantages, such as being label‐free and high throughput, yet it is a challenge for laser‐based techniques due to limited lateral resolution. Here, we develop a simple, reliable, and economic nanoscale MSI approach by introducing desorption laser with a micro‐lensed fiber. Using this integrated platform, we achieved 300 nm resolution MSI and successfully visualized the distribution of various small‐molecule drugs in subcellular locations. Exhaustive dynamic processes of anticancer drugs, including releasing from nanoparticle carriers entering nucleus of cells, can be readily acquired on an organelle scale. Considering the simplicity and universality of this nanoscale desorption device, it could be easily adapted to most of laser‐based mass spectrometry applications.
Exploring
the three-dimensional (3D) drug distribution within a
single cell at nanoscale resolution with mass spectrometry imaging
(MSI) techniques is crucial in cellular biology, yet it remains a
great challenge due to limited lateral resolution, detection sensitivities,
and reconstruction problems. Herein, a microlensed fiber laser desorption
post-ionization time-of-flight mass spectrometer (MLF-LDPI-TOFMS)
was developed for the 3D imaging of two anticancer drugs within single
cells at a 500 × 500 × 500 nm3 voxel resolution.
Nanoscale desorption was obtained with a microlensed fiber (MLF),
and a 157 nm post-ionization laser was introduced to enhance the ionization
yield. Furthermore, a new type of alignment method for 3D reconstruction
was developed on the basis of our embedded uniform circular polystyrene
microspheres (PMs). Our findings demonstrate that this 3D imaging
technique has the potential to provide information about the 3D distributions
of specific molecules at the nanoscale level.
The visualization of temporal and spatial changes in the intracellular environment has great significance for chemistry and bioscience research. Mass spectrometry imaging (MSI) plays an important role because of its unique advantages, such as being label‐free and high throughput, yet it is a challenge for laser‐based techniques due to limited lateral resolution. Here, we develop a simple, reliable, and economic nanoscale MSI approach by introducing desorption laser with a micro‐lensed fiber. Using this integrated platform, we achieved 300 nm resolution MSI and successfully visualized the distribution of various small‐molecule drugs in subcellular locations. Exhaustive dynamic processes of anticancer drugs, including releasing from nanoparticle carriers entering nucleus of cells, can be readily acquired on an organelle scale. Considering the simplicity and universality of this nanoscale desorption device, it could be easily adapted to most of laser‐based mass spectrometry applications.
Among various ionization sources for mass spectrometry, microsecond pulsed glow discharge (MP-GD) and buffer-gas-assisted laser ionization (BGA-LI) sources have the potential for direct quantitative elemental analysis of solids without the requirement of standard reference materials. The analytical potential of these two ionization sources has been evaluated by coupling them to orthogonal time-of-flight mass spectrometry (MS). A straightforward method was proposed to achieve the quantitative result: if a spectrum contains little interference and elemental peak currents are proportional to their concentrations, then the molar concentration of each element is equal to its ion current proportion in the total ion current. Two series of metal standards were applied for the evaluation. Explicit spectra with little interference can be acquired by both techniques. The interferences contribute only a very small portion to the total ion current for MP-GD-MS and BGA-LI-MS; therefore, their influence on the quantitative result can be ignored. All metal elements can be determined quite accurately by the proposed quantitation method, while gaps exist for nonmetal elements due to the high ionization potentials or gas species interference. Between the two techniques, BGA-LI-MS offers a more accurate quantitative result, primarily due to its higher plasma temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.