Diension icon microscope

The morphologies of BPNS, BATNS were characterized by transmission electron microscope (TEM, JEM-2010HR, JEOL, Japan) operating at 120 kV. Atomic force microscopy (AFM) was performed on Bruker Diension Icon microscope. The size and zeta potential of BPNS, BATNS were measured by Malvern Zetasizer Nano ZS90. The structures of BPNS, BATNS were determined by Raman scattering, X-ray photoelectron spectroscopy (XPS, Axis HSi, Kratos Ltd., UK), UV–vis–NIR spectrophotometry (Lambda 950, PerkinElmer, UK), X-ray diffraction (XRD), Inductively coupled plasma atomic emission spectrometer (ICP-AES) and Micro infrared spectrophotometry. The surface morphology and elemental distributions were analyzed by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS).

The morphology and size of nanosheets were characterized by transmission electron microscopy (TEM, HT7700 Exalens, Hitachi, Japan). Atomic force microscopy (AFM) images were acquired using a Bruker Diension Icon microscope (USA). The size/polydispersity index and zeta potential of the samples were measured on a NanoBrook Omni (NanoBrook Omni, Brookhaven Instruments Co, USA). UV–vis–NIR absorption spectra were collected using a UV–vis–NIR spectrophotometer (UV1800PC, JING HUA Instruments, China). Raman spectra were obtained on a high-resolution confocal Raman microscope (Thermo Fisher DXR 2xi, USA). The chemical compositions of the Ti NSs, Ti@PDA NSs, Ti@PDA-PEG NSs and Ti@PDA-PEG-DOX NSs were analyzed by X-ray photoelectron spectroscopy (XPS, Thermo Scientific ESCALAB 250Xi, USA). Fourier transform infrared spectroscopy (FTIR) was carried out on an IRTracer-100 (Japan) using the KBr method to monitor the synthesis process of the nanosheets.

Transmission electron microscopy (TEM) images were acquired using FEI Tecnai G2 F30 transmission electron microscope. Atomic force microscopy (AFM) was performed on Bruker Diension Icon microscope. X-ray photoelectron spectroscopy (XPS) was performed using a Kratos Axis Ultra DLD spectrometer with Al Kα radiation (1486.6 eV photons, 150 W). The size and zeta potential of samples were measured on Malvern Mastersizer 2000 (Zetasizer Nano ZS90, Malvern Instruments Ltd., United Kingdom).