Our article "Highly sensitive superconducting circuits at ∼700 kHz with tunable quality factors for image-current detection of single trapped antiprotons" has been published in Review of Scientific Instruments. There we describe highly sensitive image-current detection systems based on superconducting toroidal coils and ultra-low noise amplifiers for non-destructive measurements of the axial frequencies (550–800 kHz) of single antiprotons stored in the BASE multi-Penning-trap system. The unloaded superconducting tuned circuits show quality factors of up to 500 000. Connected to ultra-low noise amplifiers and the trap system, signal-to-noise-ratios of 30 dB at quality factors of >20 000 are achieved. In addition, we have developed a superconducting switch which allows continuous tuning of the detector’s quality factor and to sensitively tune the particle-detector interaction, being a crucial development for single antiproton spin-transition spectroscopy experiments, as well as improved measurements of the proton-to-antiproton charge-to-mass ratio.