Fluorescent Nanowire Heterostructures as a Versatile Tool for Biology Applications

Nanowires are increasingly used in biology, as sensors, as injection devices, and as model systems for toxicity studies. Currently, in situ visualization of nanowires in biological media is done using organic dyes, which are prone to photobleaching, or using microscopy methods which either yield poor resolution or require a sophisticated setup. Here we show that inherently fluorescent nanowire axial heterostructures can be used to localize and identify nanowires in cells and tissue. By synthesizing GaP–GaInP nanowire heterostructures, with nonfluorescent GaP segments and fluorescent GaInP segments, we created a barcode labeling system enabling the distinction of the nanowire morphological and chemical properties using fluorescence microscopy. The GaInP photoluminescence stability, combined with the fact that the nanowires can be coated with different materials while retaining their fluorescence, make these nanowires promising tools for biological and nanotoxicological studies

Additional file 1 of Pulmonary toxicity and translocation of gallium phosphide nanowires to secondary organs following pulmonary exposure in mice

Supplementary Material 1: Experimental details and results of the pilot study and 3-months study. GaP NW synthesis and characterization in pilot study. Table S1: Pilot study design. Figure S1: Characterization of GaP NWs in the pilot study. Table S2: (Pilot study) Cellular composition of bronchoalveolar lavage 1 and 3 days after exposure to GaP NWs. Figure S2: (Pilot study) Histopathology of mouse lung 1 and 28 days after pulmonary exposure to GaP NWs. Table S3: 3-month study design. Figure S3: Additional darkfield of GaP NWs in tissues. Figure S4: Chemical identification by EDS of GaP NWs in lung tissue 1 day after exposure. Figure S5: SEM images of GaP NWs in lung tissue day 1 and 28 and 3 months post-exposure. Table S4: Diameter of gold nanoparticles and nanowires in vivo and in vitro. Figure S6, Table S5 and S6: Cellular composition of bronchoalveolar lavage 1, 3, 28 days and 3 months after exposure to GaP NWs, carbon black or MWCNT Mitsui-7. Figure S7 and Table S7: Genotoxicity in BAL cells, lung and liver tissue in 3-month study. Table S8. Mouse lung histopathology 1, 28 days and 3 months after intratracheal instillation of GaP NWs, incidence table. Table S9: Composition of phagolysosomal simulant fluid (PSF). Table S10: Composition of low-calcium Gamble’s solution