The analysis of proteins in the gas phase benefits from detectors that exhibit high efficiency and precise spatial resolution. Although modern secondary electron multipliers already address numerous analytical requirements, new methods are desired for macromolecules at low energy. Previous studies have proven the sensitivity of superconducting detectors to high-energy particles in time-of-flight mass spectrometry. Here we explore a new energy regime and demonstrate that superconducting nanowire detectors are exceptionally well suited for quadrupole mass spectrometry. Our detectors exhibit an outstanding quantum yield at remarkably low impact energies. Notably, at low ion energy, their sensitivity surpasses conventional ion detectors by three orders of magnitude, and they offer the possibility to discriminate molecules by their impact energy and charge. By combining these detectors into arrays, we demonstrate low-energy ion beam profilometry, while our cryogenic electronics pave the way for future developments of highly integrated detectors.
@article{arxiv.2306.14571,
title = {Highly sensitive single-molecule detection in slow protein ion beams},
author = {M. Strauß and A. Shayeghi and M. F. X. Mauser and P. Geyer and T. Kostersitz and J. Salapa and O. Dobrovolskiy and S. Daly and J. Commandeur and Y. Hua and V. Köhler and M. Mayor and J. Benserhir and C. Bruschini and E. Charbon and M. Castaneda and M. Gevers and R. Gourgues and N. Kalhor and A. Fognini and M. Arndt},
journal= {arXiv preprint arXiv:2306.14571},
year = {2024}
}