@article{12940, abstract = {Desorption electrospray ionization (DESI), easy ambient sonic-spray ionization (EASI) and low-temperature plasma (LTP) ionization are powerful ambient ionization techniques for mass spectrometry. However, every single method has its limitation in terms of polarity and molecular weight of analyte molecules. After the miniaturization of every possible component of the different ion sources, we finally were able to embed two emitters and an ion transfer tubing into a small, hand-held device. The pen-like interface is connected to the mass spectrometer and a separate control unit via a bundle of flexible tubing and cables. The novel device allows the user to ionize an extended range of chemicals by simple switching between DESI, voltage-free EASI, or LTP ionization as well as to freely move the interface over a surface of interest. A mini camera, which is mounted on the tip of the pen, magnifies the desorption area and enables a simple positioning of the pen. The interface was successfully tested using different types of chemicals, pharmaceuticals, and real life samples. Moreover, the combination of optical data from the camera module and chemical data obtained by mass analysis facilitates a novel type of imaging mass spectrometry, which we name “interactive mass spectrometry imaging (IMSI)”.}, author = {Meisenbichler, Christina and Kluibenschedl, Florian and Müller, Thomas}, issn = {0003-2700}, journal = {Analytical Chemistry}, keywords = {Analytical Chemistry}, number = {21}, pages = {14314--14318}, publisher = {American Chemical Society}, title = {{A 3-in-1 hand-held ambient mass spectrometry interface for identification and 2D localization of chemicals on surfaces}}, doi = {10.1021/acs.analchem.0c02615}, volume = {92}, year = {2020}, } @article{7300, abstract = {Photoinduced electron transfer (PET), which causes pH-dependent quenching of fluorescent dyes, is more effectively introduced by phenolic groups than by amino groups which have been much more commonly used so far. That is demonstrated by fluorescence measurements involving several classes of fluorophores. Electrochemical measurements show that PET in several amino-modified dyes is thermodynamically favorable, even though it was not experimentally found, underlining the importance of kinetic aspects to the process. Consequently, the attachment of phenolic groups allows for fast and simple preparation of a wide selection of fluorescent pH-probes with tailor-made spectral properties, sensitive ranges, and individual advantages, so that a large number of applications can be realized. Fluorophores carrying phenolic groups may also be used for sensing analytes other than pH or molecular switching and signaling.}, author = {Aigner, Daniel and Freunberger, Stefan Alexander and Wilkening, Martin and Saf, Robert and Borisov, Sergey M. and Klimant, Ingo}, issn = {0003-2700}, journal = {Analytical Chemistry}, number = {18}, pages = {9293--9300}, publisher = {ACS}, title = {{Enhancing photoinduced electron transfer efficiency of fluorescent pH-probes with halogenated phenols}}, doi = {10.1021/ac502513g}, volume = {86}, year = {2014}, }