An international research team, led by quantum physicist Markus Arndt from the University of Vienna, has accomplished a groundbreaking achievement in the detection of protein ions. By harnessing the high energy sensitivity of superconducting nanowire detectors, they have attained an unparalleled quantum efficiency of nearly 100%. This astonishing feat surpasses the detection capabilities of traditional ion detectors at low energies by a staggering factor of up to 1,000. Additionally, these innovative detectors possess the unique ability to differentiate macromolecules based on their impact energy, providing a valuable enhancement to mass spectrometry in terms of sensitivity and information richness. The team’s remarkable findings were recently published in the esteemed journal Science Advances.
The detection, identification, and analysis of macromolecules, particularly proteins, hold immense importance in various areas of life sciences, such as protein research, diagnostics, and analytics. Mass spectrometry, a widely utilized detection system, employs a method that segregates charged particles (ions) according to their mass-to-charge ratio and gauges the intensity of the signals emitted by the detector. This process extracts valuable insights about the relative abundance and composition of different ion types within a given sample. However, traditional detectors have faced limitations in achieving high detection efficiency and spatial resolution for particles possessing low-impact energy. Overcoming this challenge, an international team of researchers, coordinated by the University of Vienna and consisting of partners from Single Quantum (Delft), EPFL (Lausanne), MSVision (Almere), and the University of Basel, has harnessed the potential of superconducting nanowire detectors.
In their groundbreaking study, the research consortium introduces the first-ever use of superconducting nanowires as exceptional detectors for protein beams in quadrupole mass spectrometry. The sample’s ions are fed into a quadrupole mass spectrometer, where they undergo filtration. Project leader Markus Arndt, hailing from the Quantum Nanophysics Group at the University of Vienna’s Faculty of Physics, explains that the utilization of superconducting nanowires instead of conventional detectors enables the identification of particles with low kinetic energy. This remarkable capability stems from the unique material property of the nanowire detectors – superconductivity. When exposed to extremely low temperatures, the nanowires enter a superconducting state in which their electrical resistance diminishes, enabling the flow of current without any loss. The incoming ions excite the superconducting nanowires, leading to a transition back to the normal conducting state known as a quantum transition. The change in the nanowires’ electrical properties during this transition is interpreted as a detection signal. First author Marcel Strauß elaborates, “With the nanowire detectors we use, we exploit the quantum transition from the superconducting to the normal conducting state and can thus outperform conventional ion detectors by up to three orders of magnitude.”
Indeed, nanowire detectors exhibit an extraordinary quantum yield even at remarkably low impact energies, revolutionizing the possibilities of traditional detectors. As Marcel Strauß emphasizes, “In addition, a mass spectrometer equipped with such a quantum sensor has the capacity to classify molecules not only based on their mass-to-charge state but also based on their kinetic energy. This amplifies the detection capabilities and offers the prospect of enhanced spatial resolution.” The tremendous potential of nanowire detectors extends beyond protein research, finding applications in domains like mass spectrometry, molecular spectroscopy, molecular deflectometry, and quantum interferometry of molecules. These detectors prove indispensable when high efficiency and exceptional resolution are prerequisites, particularly in scenarios involving low-impact energy.
The remarkable breakthrough achieved by Markus Arndt and his international team in the realm of protein ion detection spearheads a new era in scientific research. The utilization of superconducting nanowire detectors enables unmatched quantum efficiency, allowing for precise detection and analysis of macromolecules. By surpassing the limitations of traditional detectors, nanowire detectors offer a fresh perspective, providing invaluable advantages in mass spectrometry and other fields requiring high sensitivity and resolution. As we witness the immense potential unlocked by superconducting nanowires, it becomes clear that the future of protein research and molecular analysis holds even greater promise.