Allain (PPSM) designs luminescent and mechanofluorochromic molecular materials and lanthanide/organic probes acting as optical stress and environment sensors, including solid-state and time-resolved luminescence readouts. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work is complemented by stimuli-responsive molecular luminescent sensors.