Fluorescent nano-diamonds (fND) containing negatively charged Nitrogen Vacancy (NV) centers have remarkable applications in biology such as bio-labelling and nanoscale sensing of cellular processes. The NV centers also act as atomic scale probes that are highly sensitive to the magnitude, direction and fluctuation of local magnetic fields. The work presented here reports on the development of a wide-field microscope using fNDs as biologically targeted quantum probes to monitor live cell dynamics associated with fluctuations in local magnetic and electric fields. fNDs were functionalized using antibodies to enable site specific targeting. Strategies were also implemented to overcome the formation of endosomes around fNDs once inside the cytoplasma, which not only inhibits targeting but also the resultant sensitivity to the cellular environment. In addition to fluorescent mapping, the exchange of magnetization between the magnetically active NV defects in the diamond lattice and paramagnetic species in the local environment was studied via acquisition of optically detected magnetic resonance spectra. The results of this work demonstrate the utility of fNDs as probes to monitor subcellular dynamics. The wide-field configuration of the microscope enabled fast acquisition of images essential to characterize transient events in live cells. Looking to the future, fNDs have tremendous potential to augment existing fluorescent probes and to enable magnetic resonance measurements on a nanoscale in live cell cultures.