A universal detector for mass spectrometry and molecular science.
Mass spectrometry is ubiquitous in science and technology, from medicine and pharmacy over security surveillance to research in chemistry and physics. It requires the preparation, filtering and detection of single molecular ions. Matrix-assisted laser desorption ionisation (MALDI) and electrospray ionisation (ESI) are routinely used in the preparation of molecular ion beam and quadruple mass filters (QMF) or time-of-flight mass spectrometers (TOF-MS) are commercially successful mass analysers. However, counting very massive, lowly charged or even neutral molecules fast and efficiently has remained a grand challenge. In most realisation, ions are counted by accelerating them onto a high-voltage dynode. The few electrons released from the surface are then further amplified in secondary electron multipliers. To be efficient, this process requires the incident ion to surpass a velocity of more than 2×104 m/s, which is technologically demanding for massive proteins. Realising a particle detector that can count macro-molecules even at low energies with near-100% efficiency would be highly desirable, also because the mass-resolution of time-of-flight spectrometers grows with the transit time of the ions through the instrument. A novel energy-sensitive detector shall also open the door to an entire branch of new research on beams of neutral single bio-molecules in the gas phase, with applications in single molecule UV/VIS/IR spectroscopy, molecular deflectometry and quantum optics.
SUMO: superconducting nano-wire detector technology, scalable into an integrated cryogenic camera for neutral and charged molecules/nano-particles
We propose to explore the ground for a scalable superconducting particle detector technology. We will focus on superconducting nano-wire detectors (SNWD), which have become available as small chips for applications in fast and efficient single-photon detection. First studies have also shown that SNWDs can detect molecular ions. However, many technological challenges still need to be addressed to prove the concept is sustainable and the detection of neutral molecules is still an open field of research. The wire geometry needs to be balanced between detector area, sensitivity, speed, robustness and scalability. The dependence of the detection efficiency on kinetic energy needs to be evaluated. The specific role of the internal molecular state as well as the energy exchange with the SNWD open new research questions and technology challenges. SUMO serves as a pilot study to demonstrate the potential of this technology. In its second stage it shall be up-scaled into a full SNWD array with cryogenic amplification, signal conversion and storage. A cryogenic particle camera has the potential of becoming a game changer in mass spectrometry and quantum thermal spectroscopy for bio-polymer research.