Fluorescent nanosensor probes have suffered from limited mol. recognition and a dearth of strategies for spatial-temporal operation in cell culture. In this work, we spatially imaged the dynamics of nitric oxide (NO) signaling, important in numerous pathologies and physiol. functions, using intracellular near-IR fluorescent single-walled carbon nanotubes. The obsd. spatial-temporal NO signaling gradients clarify and refine the existing paradigm of NO signaling based on averaged local concns. This work enables the study of transient intracellular phenomena assocd. with signaling and therapeutics. [on SciFinder(R)]