摘要： Advancing the frontiers of nanoscience and information technology hinges on the availability of novel tools for nanoscale sensing and imaging. Solid-state electronic spins offer a unique platform to implement high-performance quantum sensing devices, which address this need and go beyond what classical technologies offer. We present a robust technology to realise this concept, which is based on nano-engineered diamond devices, hosting single electronic spins for sensing. We will describe the key principles underlying these novel quantum sensors and discuss some of their areas of applications which we have opened over the last years. These include the field of antiferromagnetic spintronics, where single spin magnetometry already yields unprecedented insight into domain formation and non-trivial spin-textures in antiferromagnets. Next to these room-temperature applications, we will present results of cryogenic single spin magnetometry for quantitative, high resolution imaging of vortices and supercurrents in nanoscale superconductors. These examples illustrate the remarkable performance that single spin quantum sensing offers, and which holds great promise for future applications in various applicatons of the nano-sciences.