Applications of Single Nanotube Imaging Spectroscopy in Live Cells

The intrinsic near-infrared photoluminescence from a single nanotube can be detected within a live cell via epifluorescence. As the emission spectrum of a nanotube is exquisitely modulated by the immediate microenvironment of the nanotube, information contained in the peak emission wavelength, intensity, and full width half maximum can reflect physicochemical properties of the microenvironment. We have developed methods for detecting metabolites by employing changes in carbon nanotube emission.  By spatially localizing a polymer-functionalized nanotube to a subcellular organelle, and by measuring the spectral response of the nanotube to its environment, we demonstrate the use of single nanotube spectroscopy to quantify specific metabolites in live cells.