Monitoring oocyte/embryo respiration using electrochemical-based oxygen sensors

•A three-electrode, Clark-type biosensor for mitochondrial respirometry in single oocytes and embryos is presented.•The sensor measured basal respiration, respiration associated with proton leak, and the maximal respiratory capacity.•The sensor can be used to analyze mitochondrial function in oocytes to determine the quality and viability of their development into embryos.