Ti e a1 si

Unless otherwise stated, all reagents and solvents were of analytical grade, which were obtained directly from commercial suppliers without further purification. 6-Hydroxy-2-naphthaldehyde, 2-aminothiophenol, p-toluenesulfonic acid monohydrate, and dimethylcarbamothioic chloride were all purchased directly from Sigma. The secondary distilled water was used throughout all over the experiment. The ¹H NMR and ¹³C NMR spectra were measured by Bruker 400 M nuclear magnetic resonance spectrometer using d₆-DMSO as the solvent, in which chemical shifts are in ppm and tetramethylsilane (TMS) is used as an internal standard. The mass spectra of different systems were measured on Bruker solanX 70 FT-MS. All fluorescence measurements were measured in the G9800A fluorescence spectrophotometer (Agilent, USA) at the slits of 5.0/5.0 nm. The pH was measured using a METTLER TOLEDO FE-28 pH; Fluorescence imaging of HeLa cells was obtained by Nikon confocal microscopy (Ti-E+A1 SI).

Confocal laser scanning microscopic imaging (CLSM) was performed by TI-E+A1 SI, Nikon confocal laser scanning microscope with Ar laser. Adsorption spectra were performed on a UV-vis 2600 spectrophotometer (Shimadzu). Fluorescence spectra were recorded from F-7000 fluorescence spectrometer (Hitachi). Dynamic light scattering measurements and zeta potential measurements were performed by Nano Zetasizer analyzer (Malvern) with Dispersion Technology Software. Flow cytometer were conducted on Gallios Flow Cytometer (Beckman Coulter).

UV-vis spectra and transmission electron microscopy (TEM) images were obtained using a UV-1800 spectrophotometer using 1 cm quartz cells (Shimadzu, Japan) and a JEM-2100F microscope (JEOL, Japan), respectively. For TEM characterization, the samples were prepared by drying a drop of dilute particle dispersion on a carbon-coated Cu grid. Fluorescence spectra were measured using a F-4600 fluorescence spectrophotometer (Hitachi, Tokyo, Japan) under the excitation of a 560 nm laser. Confocal laser scanning microscopy images were recorded on a TI-E + A1 SI, Nikon.