Embodiments of the present disclosure pertain to methods of monitoring an environment for the presence of a solvent by: (i) exposing the environment to a luminescent compound, where the relative luminescence emission intensity of the luminescent compound changes upon interaction with the solvent; and (ii) monitoring a change in the relative luminescence emission intensity of the luminescent compound, where the absence of the change indicates the absence of the solvent from the environment, and where the presence of the change indicates the presence of the solvent in the environment. The luminescent compounds include a phosphorous atom with one or more carboxyl groups, where the carboxyl groups are coordinated with one or more metallic ions (e.g., lanthanide ions and yttrium ions). The present disclosure also pertains to sensors for monitoring an environment for the presence of a solvent, where the sensors include one or more of the aforementioned luminescent compounds.