Boxer's group uses vibrational Stark effect spectroscopy -- measuring field-dependent shifts of nitrile, carbonyl, and other IR-active vibrational probes -- to quantify electrostatic fields inside proteins, membranes, and active sites, providing a molecular-scale, spectroscopic route to electric-field sensing distinct from device-based quantum sensors. [Borderline match: a molecular spectroscopic probe of local fields rather than a fabricated quantum sensor; kept for review.]