A submersible EPR-on-a-chip dipstick sensor for applications in harsh environments #EPR #Instrumentation

Published: Sunday, 14 April 2024 - 10:00 -0400

Author: Thorsten Maly

Hi everyone,

I hope you are all having a wonderful week. I would like to invite you to the next International EPR society virtual seminar, which will occur on Wednesday, April 17th. Silvio K?nstner from Helmholtz-Zentrum Berlin will present his work on:

A submersible EPR-on-a-chip dipstick sensor for applications in harsh environments

Electron paramagnetic resonance (EPR) is the method of choice to investigate and quantify paramagnetic species in many applications in materials science, biology, and chemistry. In these fields, typical sample states include thin films and solutions. Of particular interest are dynamic processes in solution. Their investigation, however, is limited by the form factor of the utilized microwave (MW) resonators as the entire process needs to be confined to the resonator. The EPR-on-a-Chip (EPRoC) dipstick device circumvents these limitations by integrating the entire EPR spectrometer into a single microchip, covered with a protective coating that enables the operation of the EPRoC submerged directly in the sample solution, thereby expanding the accessible sample environments for EPR measurements. In this approach, instead of a MW resonator, the coil of a voltage-controlled oscillator (VCO) with a size of a few hundred micrometers is simultaneously used as MW source and detector.

As a test for the EPRoC dipstick and its protective coating, differently charged electrolyte solutions of a Vanadium redox flow battery with pH < 1 were investigated with the EPRoC and compared to conventional EPR results. The same linear relationship of EPRoC and EPR signal intensities with respect to the state of charge (SOC) was found, so that these experiments serve as proof-of-principle for a quantitative EPRoC dipstick device operating in a harsh sample environment. Dipstick EPRoC with its inherent fast rapid scan (RS) capability using frequency sweeps allows the investigation of processes, in which time resolution is important. It has been shown recently that the SNR per allocated acquisition time can significantly be enhanced, if measurement time for obtaining a full spectrum is the limiting factor, such as in oximetry. In combination with a permanent magnet, of which a first prototype will be presented, the EPRoC dipstick may find its way beyond the laboratory as a quantification tool for paramagnetic species in solution.

Webinar details:
Time: Wednesday, April 17th, 2024, 6:00 AM California/ 9:00 AM Boston/ 3:00 PM Paris/ 7:30 PM Delhi

Webinar Link: https://fsu.zoom.us/j/95942948386?pwd=WHM0T3ZyL1pEQzFaRnRnYVdBZUdJdz09
Password: IVEM

Feel free to forward this invitation to your groups and any other interested colleagues. More information can be found on our website, including information on how to join our mailing list and links to previous seminars on our youtube channel: https://www.eprseminars.org

If you have any questions, feel free to contact anyone on the IVEM team, see the about us section of our website for contact information.

With warm regards,
Joseph

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