Uv 2450 spectrophotometer

All nuclear magnetic resonance (NMR) spectra of BPN-NBD were collected by a Bruker Avance 400 MHz spectrometer. A Zeiss LSM710 Wetzlar (German) laser scanning confocal microscope was used for fluorescence imaging. High-resolution mass spectrometry (HRMS) data of new compounds were tested on AB Sciex TripleTOF 4600. UV–vis absorption and fluorescence data were collected through a Shimadzu UV-2450 spectrophotometer and a HITACHI F-4600 fluorescence spectrophotometer, respectively. Ultra-high performance liquid chromatography (UHPLC) analyses were conducted on a Shimadzu NexeraX2 UHPLC LC-30A. Unless otherwise specified, all raw materials used for synthesis were purchased from the chemical suppliers in China and used directly without further refining.

High-resolution transmission electron microscopy (HR-TEM) pictures were collected at 100 kV using a TECNAI G2 microscope (Thermo Fisher, Waltham, MA, USA). The image of scanning electron micrographs (SEM) was measured by a XL-30ESEM FEG scanning electron microscope (FEI, Hillsboro, OR, USA). FTIR spectra were conducted with a VERTEX 70 FT-IR spectrometer (Bruker, Bremen, Germany). The X-ray photoelectron spectroscopy (XPS) spectra were acquired using an ESCALAB 250Xi spectrometer (Thermo Fisher, Waltham, MA, USA). A Rigaku Minister apparatus was used to generate the X-ray diffraction (XRD) patterns (Tokyo, Japan). The UV absorption spectra were performed via a Hitachi UV2450 spectrophotometer (Tokyo, Japan). The fluorescence spectra were obtained using an F97Pro FL spectrophotometer coupled with a 1.0-cm quartz cell (Lengguang Technology, Shanghai, China). Additionally, the fluorescent, phosphorescent lifetime, and emission spectrum were analyzed at room temperature using an FLS-1000 fluorescence spectrophotometer (Edinburgh, UK).