The measurement of cellular metabolism involves observation of multiple metabolites. Chemical reaction pathways which occur within the cell may be measured in the extracellular matrix. A fluorophore/polymer based portable sensor was developed which does not consume metabolites, is noninvasive, improves sensor measurements and may be used in standard 24-well plates. The sensor rapidly detects physiological changes without contaminating cell cultures with fluorescent dyes. The sensor uses an oxygen sensitive fluorophore, platinum octaethylporphyrin, embedded in a polymer matrix to measure extracellular O2 concentration changes in response to an external physiological antagonist. The sensor design was able to acquire real-time measurement of metabolite concentration changes in the extracellular matrix.