U 3900 ultraviolet visible uv vis spectrophotometer

Poly (9,9-dioctylfluorene-2,7-diyl) (PFO) and poly (styrene-co-maleic anhydride) (PSMA) were purchased from Sigma-Aldrich. Tetrahydrofuran (THF; anhydrous, ≥99.9%, inhibitor-free), diphenylcarbazide (DPC), K₂Cr₂O₇, NaCl, MgCl₂, KCl, CaCl₂, FeCl₃ 6H₂O, CuCl₂ 2H₂O, NiCl₂, KMnO₄, acetic acid, boric acid, phosphoric acid, HCl and NaOH were obtained from Sinopharm Chemical Reagent Co., Ltd. (Shangai, China).
The apparatus used in the work included a transmission electron microscope (Talos F200X G2, Thermo Fisher, Waltam, MA, USA); dynamic light scattering system (DLS, Malvern Zetasizer Nano ZS, Malvern, United Kingdom); U-3900 ultraviolet–visible (UV–vis) spectrophotometer (Hitachi, Japan); F-7000 fluorescence spectrophotometer (Hitachi, Japan) and Laser Scanning Confocal Microscopy (Carl Zeiss, Germany).

All reagents were purchased from commercial sources (Innochem (Beijing, China), TCI (Shanghai, China), Sigma-Aldrich (Shanghai, China), Adamas-beta (Shanghai, China), Aladdin (Shanghai, China)) and used without further purification. All solvents and inorganic salts were purchased from Beijing Reagent, Sinopharm Chemical Reagent Beijing or General-Reagent, and used without further processing. Human cervical carcinoma cells (HeLa cells), human hepatocarcinoma cells (HepG-2 cells), human non-small cell lung cancer cell (A549 cells), and Human Umbilical Vein Endothelial Cells (HU-EVC cells) were purchased from the Center of Cells, Peking Union Medical College.
¹H NMR and ¹³C NMR spectra were obtained with Bruker Avance III 400 and Ascend 600 MHz spectrometers (Karlsruhe, Germany), respectively, using CDCl₃ or DMSO-d₆ as a solvent, and tetramethylsilane (TMS) was used as an internal standard. Electrospray Ionization Mass Spectrometry (ESI-MS) was conducted using a Thermo Fisher Scientific Q-Exactive spectrometer (Waltham, MA, USA). Absorption spectra were recorded on a Hitachi U-3900 ultraviolet–visible (UV-Vis) spectrophotometer (Tokyo, Japan). Fluorescence spectra were recorded on a Hitachi F-4600 spectrofluorometer (Tokyo, Japan). Absolute fluorescence quantum yields were measured in a Quantaurus-QY absolute PL quantum yield spectrometer C11347 (Hamamatsu, Shizuoka, Japan).