Ff875 di01

Nanotubes were excited by a tunable Ti:Sa laser to preferentially excite (6,5) SWCNTs at the resonance of the dark K-momentum exciton. The beam was focused into the back aperture of a high NA objective (60×, NA 1.0) mounted on an upright microscope (Nikon, Tokyo, Japan), with an excitation intensity of 10 kW/cm² of circularly polarized light at the sample. The fluorescence was collected with the same objective and imaged on a low noise EMCCD camera (Roper Scientific SAS, Evry, France) to produce wide-field images of individual SWCNTs. A dichroic mirror (FF875-Di01, Semrock, Rochester, NY, USA) and the combination of long- and short-pass emission filters (ET900LP, Chroma Technology Corp., Bellows Falls, VT, USA; FESH1000, Thorlabs SAS, Maisons-Laffitte, France) were used in order to illuminate and detect the (6,5) SWCNTs’ emitted fluorescence. Images of SWCNTs were recorded with 30 ms integration time per frame.

The tissue slices were first incubated with SWCNT for ~2 h, and then the slices were mounted in a ludin chamber for image acquisition. The ludin chamber was filled with artificial cerebrospinal fluid solution (126 mM NaCl, 3.5 mM KCl, 2 mM CaCl₂, 1.3 mM MgCl₂, 1.2 mM NaH₂PO₄, 25 mM NaHCO₃ and 12.1 mM glucose; gassed with 95% O₂: 5% CO₂; pH 7.35) at room temperature. (6,5)-SWCNTs were selectively excited within the tissue at 845 nm by a tunable Ti-sapphire laser (Spectra Physics, Model 3900S) and 985 nm by a diode laser (Thorlabs). The incident laser beam, circularly-polarized at the sample to ensure that SWCNTs are excited regardless of their orientation in the sample plane, was focused into the back aperture of an objective (Nikon, 60x, NA 1.0) mounted on an upright microscope (Nikon TiE eclipse; Tokyo, Japan). The emission was collected with the same objective and imaged on the same camera to produce wide-field images of individual SWCNTs within the tissue. A dichroic mirror (FF875-Di01; Semrock, Rochester, NY, USA) and the combination of long-pass emission filters (ET900LP, Chroma Technology Corp. and RazorEdge 1064, Semrock) were used to illuminate and detect PL of SWCNTs inside deep tissues. Images of SWCNTs were recorded with 30 ms integration time per frame.