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Laser assisted paper spray ionization mass spectrometry (LAPSI MS), ambient ionization technique used for monitoring in situ photoassisted reactions like the decarboxylation of mercaptobenzoic acid in the presence of gold and silver nanoparticles. Negative ion detection demonstrated due to the capture of produced photoelectrons distorted electronic states of reduced ionization energy.

Materials are making inroads into mass spectrometry, and an example is the use of advanced materials for enhanced ionization by transformation of a less-ionizable molecule to an easily ionizable one. The use of Pt nanoparticle-decorated nanotubes as highly active catalysts for the reduction of 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene and subsequent easy detection of the product by in situ ambient ionization mass spectrometry.

The ionization of molecular species from one-dimensional (1D) tellurium nanowires (Te NWs) is achieved at 1 V. Molecules with a range of chemical functional groups gave quality mass spectra with high signal/noise ratios and no fragment ions. Analysis of a variety of analytes, including amino acids, pesticides, and drugs, in pure form and in complex mixtures is reported. These experiments suggest that 1D nanostructures are an excellent ionization sources.

The article presents the analytical performance and a suggested mechanism for zero volt paper spray using chromatography paper. The zero volt paper spray is compared with standard kV paper spray (PS) ionization and nanoelectrospray ionization (nESI). Although the range of analytes to which zero volt PS is applicable is very similar to kV PS and nESI, differences in the mass spectra of mixtures are construed in terms of the more significant effects of analyte surface activity in the gentler zero volt experiment than in the other methods due to the significantly lower charge; moreover, the signal intensity of zero volt PS is also lower compared to the other methods.

Here, we report the synthesis of monolayer protected, luminescent and atomically precise silver sulfide (Ag2S) clusters. Cluster formation was studied by varying the conditions of the reaction. Matrix assisted laser desorption ionization mass spectrometry (MALDI MS) was used to monitor the growth of clusters to nanoparticles (NPs). Clusters of different nuclearity were obtained at a lower temperature, and were efficiently separated by thin layer chromatography (TLC). One of the clusters was assigned as Ag158S79(SBB)32, where SBB is 4-tert-butylbenzyl mercaptan. [ABSTRACT FROM AUTHOR]

Electrolytic spray deposition was used to pattern surfaces with 2D metallic nanostructures. Spots that contain silver nanoparticles (AgNP) were created by landing solvated silver ions at desired locations using electrically floated masks to focus the metal ions to an area as little as 20 mm in diameter. The AgNPs formed are unprotected and their aggregates can be used for surface-enhanced Raman spectroscopy (SERS). The morphology and SERS activity of the NP structures were controlled by the surface coverage of landed silver ions. The NP structures created could be used as substrates onto which SERS samples were deposited or prepared directly on top of predeposited samples of interest. The evenly distributed hot spots in the micron-sized aggregates had an average SERS enhancement factor of 108. The surfaces showed SERS activity when using lasers of different wavelengths (532, 633, and 785 nm) and were stable in air. [ABSTRACT FROM AUTHOR]

In article number 1800052, Thalappil Pradeep and co‐workers introduce an easy, ambient method for creating nanopores in single‐layer molybdenum disulfide (MoS2) nanosheets (NSs) by electrospray deposition (ESD) of silver ions on a water suspension of the former. The technique using holey MoS2 NSs exhibits up to 105 times higher water disinfection efficiency compared to normal MoS2 NSs. [ABSTRACT FROM AUTHOR]

A new method for creating nanopores in single-layer molybdenum disulfide (MoS 2 ) nanosheets (NSs) by the electrospray deposition of silver ions on a water suspension of the former is introduced. Electrospray-deposited silver ions react with the MoS 2 NSs at the liquid-air interface, resulting in Ag 2 S nanoparticles which enter the solution, leaving the NSs with holes of 3-5 nm diameter. Specific reaction with the S of MoS 2 NSs leads to Mo-rich edges. Such Mo-rich defects are highly efficient for the generation of active oxygen species such as H 2 O 2 under visible light which causes efficient disinfection of water. 10 5 times higher efficiency in disinfection for the holey MoS 2 NSs in comparison to normal MoS 2 NSs is shown. Experiments are performed with multiple bacterial strains and a virus strain, demonstrating the utility of the method for practical applications. A conceptual prototype is also presented., Competing Interests: The authors declare no conflict of interest., (© 2018 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.)

Electrolytic spray deposition was used to pattern surfaces with 2D metallic nanostructures. Spots that contain silver nanoparticles (AgNP) were created by landing solvated silver ions at desired locations using electrically floated masks to focus the metal ions to an area as little as 20 μm in diameter. The AgNPs formed are unprotected and their aggregates can be used for surface-enhanced Raman spectroscopy (SERS). The morphology and SERS activity of the NP structures were controlled by the surface coverage of landed silver ions. The NP structures created could be used as substrates onto which SERS samples were deposited or prepared directly on top of predeposited samples of interest. The evenly distributed hot spots in the micron-sized aggregates had an average SERS enhancement factor of 10(8) . The surfaces showed SERS activity when using lasers of different wavelengths (532, 633, and 785 nm) and were stable in air., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ambient ionization is achieved by spraying from a carbon nanotube (CNT)-impregnated paper surface under the influence of small voltages (≥3 V). Organic molecules give simple high-quality mass spectra without fragmentation in the positive or negative ion modes. Conventional field ionization is ruled out, and it appears that field emission of microdroplets occurs. Microscopic examination of the CNT paper confirms that the nanoscale features at the paper surface are responsible for the high electric fields. Raman spectra imply substantial current flows in the nanotubes. The performance of this analytical method was demonstrated for a range of volatile and nonvolatile compounds and a variety of matrices., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)