VOLTAGE SENSITIVE DYES

Voltage sensitive dyes comprising boron and related compositions and methods are provided. In some embodiments, a voltage sensitive dye comprises an electron acceptor comprising boron. The electron acceptor may be attached (e.g., covalently) to at least one electron donating group and at least one polar group. For instance, the electron acceptor may comprise optionally substituted boron dipyrromethene (e.g., optionally substituted 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene). The point of attachment and chemical nature of the electron donating group(s) and polar group(s) may be selected to impart beneficial properties to the voltage sensitive dye. For instance, the voltage sensitive dye may have an extended difference in the dipole moment between the ground and electronic states due at least in part to the position of the electron donating group(s). The voltage sensitive dyes, described herein, may have high specificity, high signal to noise ratio, fast responsivity, high voltage sensitivity, high photostability, and/or high brightness.