Doc. dr. Matjaž Humar from the Department of Condensed Matter Physics at Jožef Stefan Institute, and researchers from UK, USA and Japan have published an article titled Whispering-gallery-mode sensors for biological and physical sensing in Nature Reviews Methods Primers. In the paper the authors introduce whispering-gallery-mode microcavities in different geometries, such as microspheres, microtoroids, microcapillaries and microrings. Whispering-gallery-mode microcavities are miniature micro-interferometers that use the multiple-cavity passes of light for very sensitive measurements at the microscale and nanoscale, including single-molecule and ion measurements. The authors describe sensing mechanisms, including mode splitting and resonance shift, and optomechanical and optoplasmonic signal transductions. Applications and experimental results cover in-vivo and single-molecule sensing, gyroscopes and microcavity quantum electrodynamics.