Plasmonic nanowells have been accepted as effective nanomaterials for LDI-MS recognition of many small molecules, although their uses in mass spectrometry (MSI) imaging are not well established. A study in the article ACS Applied Nano Materials reported the development and optimization of [email protected] nanoshells with custom compositions and structures for high-sensitivity LDI-MS analysis and a variety of MSI base applications.
Study: Laser gold nanoshell-assisted laser desorption / ionization mass spectrometry for small biomolecule analysis and tissue imaging. Image credit: Carl Dupont / Shutterstock.com
Image by mass spectrometry
Mass spectrometry imaging (MSI) has become a popular unlabeled method that allows spatial clarity of a wide range of analytes, including drugs, lipids, peptides, small biomolecules, and proteins present in various complex samples. , such as individual cells and biological tissues. .
Due to its upper limit of detection (LOD), high productivity, high salt tolerance and minimum sample consumption, matrix-assisted laser desorption / ionization (MALDI) has become one of the methods essential for MSI.
Disadvantages of MALDI
Although widely used, the approach has a number of inherent drawbacks related to organic matrices, such as poor point-to-point reproducibility, significant background interference ions in low-mass areas, and occasionally a reduced ionic yield to tiny molecules.
Due to heterogeneous cocrystallization, it is still difficult to implant a film consisting of organic matrices in the tissue coating, which can lead to a decrease in tissue image resolution.
Recrystallization is essential to address the extraction of weak analytes to achieve good ionization yields, and much attention has been paid to minimizing this phenomenon. Therefore, the creation of an array-free LDI technique with the combined advantages of enhanced tissue imaging capabilities and recognition sensitivity is especially desirable with respect to mapping the spatial distribution of small molecules.
Inorganic nanomaterials that absorb ultraviolet
Inorganic nanomaterials that absorb ultraviolet (UV) light, such as those based on silicon, carbon, composite nanomaterials, metal nanoparticles (NP), metal oxide NP, and metal-organic frames (MOFs), have attracted much attention. These newly developed nanomaterials have advantages such as low thermal conductivity, excellent light absorption, high electrical conductivity and a large surface to volume ratio.
Although the fine architectures of nanomaterials vary, regardless of spraying or spraying, their nanometric characteristics often produce a homogeneous coating surface, making them suitable candidates for MSI testing and tissue imaging.
Metal-based nanoparticles
An effective alternative for monitoring endogenous metabolites present in animal and plant tissues is to use metal oxide NP. The high boiling and melting points of these NPs make them resistant to ionization, resulting in a clear mass spectrum with high limiting background signals.
Plasmonic nanomaterials
To meet the growing demand for fast, specific and sensitive detection of small biomolecules, nanomaterials composed with synergistic action have attracted great attention. Plasmonic nanomaterials have been extensively investigated for LDIMS and tissue imaging of different metabolites due to hot carrier characteristics and localized surface plasmon resonance (LSPR).
However, according to several studies, they present problems such as unavoidable aggregations and inadequate thermal conductivity. An ongoing effort has been made to create plasmon nucleus nanoparticles for sensitive analysis of metabolites in a variety of biological samples to address these limitations.
Silicon-based nanomaterials
To obtain effective LDI-MS for metabolites present in human biofluid samples, a variety of silica core-based nanoshells have been presented. To provide distinctive metabolic fingerprints, a number of plasmonic bimetallic / trimetallic alloys have also been produced. Despite significant efforts, the excellent performance of plasmon nucleus nanoparticles and high potential for LDI-MS and tissue imaging in practical implementations are not at all optimal.
In this work, a series of [email protected] Nucleus shell NPs that had controllable nanoshell frames were achieved by a multi-cycle reduction reaction of Au3 + ions with the SiO2 sphere film. The production procedure is simple, repeatable and minimally reactive.
SiO2 @ Au nanosells show improved performance in the evaluation of numerous small compounds with significantly less background interference, compared to typical organic matrices, due to enhanced photoelectric effects, hot carrier generation, and local heating.
Important discoveries
Three things could explain why these plasmonic gold nanoscells have better tissue imaging characteristics than current nanomaterials with a single composition. First, SiO2 @ Au nanoshells have a significantly high light-to-heat conversion efficiency. Second, the roughness of the nanometer scale provides a particular crack area for the specific capture of cations and small molecules of intricate biological mixtures. Finally, the negatively charged layer favors the creation of a cation layer during the ionization procedure. All of these factors contribute to high ion performance.
Lipid species and small molecule metabolites can be observed spatially in strawberry tissues, mouse brain tissues, and tissues throughout the body of bees and zebrafish due to nanoscale size and the homogeneous layer of SiO2 nanowells. @Au. These specific tests show that the capabilities of plasmon-based nanoshell materials can be enhanced for use in practical MSI applications.
Reference
Du, M., Chen, D. et al. (2022). Laser gold nanoshell-assisted laser desorption / ionization mass spectrometry (LDI-MS) for small biomolecule analysis and tissue imaging. Available at: https://doi.org/10.1021/acsanm.2c01850
Disclaimer: The views expressed herein are those of the author expressed in private and do not necessarily represent the views of AZoM.com Limited T / A AZoNetwork the owner and operator of this website. This disclaimer is part of the Terms and Conditions of Use of this website.