Ht 7700

The morphology and size of N,S-CDs were analyzed by transmission electron microscope (HT-7700, Japan) operated at 100 kV. Fourier transform infrared (FT-IR) spectra were obtained on a Thermo Scientific Nicolet iS5 IR spectrometer (USA) ranging from 400 to 4000 cm⁻¹ using attenuated total reflection (ATR) accessory. XPS analysis was measured by Thermo Scientific ESCALAB Xi⁺ X-ray photoelectron spectrometer (USA) using Al Kα as the excitation source (1486.6 eV).

Agilent 1,290 series UHPLC system (Agilent Technologies Co., Ltd., USA) coupled with a high speed binary pump and a diode array detector (DAD) was used for the quantitative analysis of the pyrethroid insecticides. The separation of target analytes was carried out on Agilent SB-C₁₈ column (2.1 × 100 mm, 1.8 μm). The detection wavelength was set at 210 nm. The mobile phases were (A) water and (B) acetonitrile with the gradient as follows: 70–90% (B) for 0–5 min, 90–100% (B) for 5–8 min and then a re-equilibration of 5 min. After being filtered through 0.22 μm filter, the sample solution of 2 μL was injected to UHPLC system and analyzed at 35°C with the flow rate at 0.4 mL/min. The SEM (Hitachi S4800, Tokyo, Japan), TEM (Hitachi HT-7700, Tokyo, Japan) and FT-IR (Thermo Scientific Nicolet iS5 spectrometer, Madison, USA) were used for the characterization of DES, graphene and DES-G.

The particle size distribution of mPEG-PGNSs, mPEG/HER-PGNSs, DM1-PGNSs and DM1-mPEG/HER-PGNSs (prepared as described in the supporting information) were determined by dynamic light scattering (DLS) on a Zetasizer Nano-ZS90 device (Malvern Instruments, UK). The SPR absorption spectra ranging from 400 to 1000 nm were obtained using a UV–vis spectrophotometer (UV1200, Agilent, USA) at 25 °C. The morphologies and sizes of the PGNSs were examined using TEM (HT7700, Japan) with a CCD camera operating at an accelerating voltage of 100 kV. FTIR spectroscopy (Nicolet iS10, Thermo Fisher, USA) was used to define the formation of the Au–S bonds between mPEG and the PGNSs. The synthesized PGNSs and mPEG/HER-PGNSs were subjected to XRD analysis using a D8 Advance X-ray Diffractometer (Bruker Analytical Instruments Pvt. Ltd., Germany).