Matthias Polack

• Master of Science
• Leipzig University

This study presents the development of a miniaturized device for supercritical fluid chromatography coupled with mass spectrometry. The chip-based, modular nanoSFC approach utilizes a particle-packed nanobore column embedded between two monolithically structured glass chips. A microtee in the pre-column section ensures picoliter sample loads onto t...

Droplet microfluidics provides an efficient method for analysing reactions within the range of nanoliters to picoliters. However, the sensitive, label-free and versatile detection with ESI/MS poses some difficulties. One challenge is the difficult association of droplets with the MS signal in high-throughput droplet analysis. Hence, a droplet-on-de...

This work presents a novel microfluidic screening setup with real-time analytics for investigating reactions with immobilised biocatalysts. The setup combines microreactor technology, multi-reactor integration, and online (chip-)LC/MS analysis in a sequential automated workflow. We utilized in-house manufactured fused-silica glass chips as reusable...

This work presents a novel microfluidic screening setup with real-time analytics for investigating reactions with immobilised biocatalysts. The setup combines microreactor technology, multi-reactor integration, and online (chip-)LC/MS analysis in a...

Ambient mass spectrometry imaging (MSI) is a powerful technique that allows for the simultaneous mapping of hundreds of molecules in biological samples under atmospheric conditions, requiring minimal sample preparation. We have developed nanospray desorption electrospray ionization (nano-DESI), a liquid extraction-based ambient ionization technique...

We report a novel approach for surface-enhanced Raman spectroscopy (SERS) detection in digital microfluidics (DMF). This is made possible by a microspray hole (μSH) that uses an electrostatic spray (ESTAS) for sample transfer from inside the chip to an external SERS substrate. To realize this, a new ESTAS-compatible stationary SERS substrate was de...

Microfluidic double-emulsion droplets allow the realization and study of biphasic chemical processes such as chemical reactions or extractions on the nanoliter scale. Double emulsions of the rare type (o 1 /w/o 2 ) are used here to realize a lipase-catalyzed reaction in the non-polar phase. The surrounding aqueous phase induces the transfer of the...

Improving the performance of chemical transformations catalysed by microbial biocatalysts requires a deep understanding of cellular processes. While the cellular heterogeneity of cellular characteristics, such as the concentration of high abundant cellular content, is well studied, little is known about the reactivity of individual cells and its im...

We report an approach for the online coupling of digital microfluidics (DMF) with mass spectrometry (MS) using a chip-integrated microspray hole (μSH). The technique uses an adapted electrostatic spray ionization (ESTASI) method to spray a portion of a sample droplet through a microhole in the cover plate, allowing its chemical content to be analyz...

Improving the performance of chemical transformations catalysed by microbial biocatalysts requires a deep understanding of cellular processes. While the cellular heterogeneity of cellular characteristics, such as the concentration of high abundant cellular content, is well studied, little is known about the reactivity of individual cells and its im...

In this work, we introduce an approach to merge droplet microfluidics with an HPLC/MS functionality on a single chip to analyze the contents of individual droplets. This is achieved by a mechanical rotor-stator interface that precisely positions a microstructured PEEK rotor on a microfluidic chip in a pressure-tight manner. The developed full-body...