Compounds, systems, and methods for monitoring and treating a surface of a subject

Compounds, systems, and methods are provided for the design and assembly of a non-invasive, analyte sensing dressing that includes a sensor and a matrix. The sensor is capable of detecting analytes such as molecular oxygen. The matrix is at least partially permeable to the analyte. In one version of the dressing, the sensor includes a meso-unsubstituted metallated porphyrin that is sensitive towards oxygen. The metallated porphyrin can be excited when illuminated at a first wavelength, followed by emission of phosphorescence at a second wavelength whose intensity can be used as an indicator for oxygen concentration. The metallated porphyrin can be prepared from a phosphorescent meso-unsubstituted porphyrin having the Formula (I):wherein M is a metal, wherein each R is independently an atom or a group of atoms, and wherein at least one R is -O(C)OR′, wherein R′ is optionally substituted alkyl.