μ quant microplate reader

A Malvern Zetasizer Nano instrument and the associated Zetasizer software were used to determine the hydrodynamic diameter, polydispersity index and zeta potential of particles in water via dynamic light scattering (DLS)( Malvern, UK). Samples were diluted with water (0.1 mg/mL) and sonicated for 10 min prior to DLS analysis. Images of the particles were acquired with a Hitachi S4800 scanning electron microscope (SEM) at 5 kV. For SEM imaging, the nanodiamond suspension was processed by adding a drop of the nanosuspension onto an SEM (Hitachi Europe Ltd, Berkshire, UK) stub and allowing the solvent (water) to evaporate. Solid samples were directly attached to the stub using conductive double-sided carbon tape. Infrared spectroscopic data were obtained using a Vertex 70 Fourier Transform Infrared (FTIR) Spectrometer (Bruker, Brighton, UK). Optical properties were investigated using a μ-Quant Microplate Reader and a Fluorescence Lifetime Spectrometer (FLS) 1000 (Edinburgh Instruments). To obtain fluorescence spectra, samples were prepared at a concentration of 0.1 mg/ml and analysed using a front-face sample holder, 590 nm emission filter and excitation/emission bandwidths of 0.8–3 nm. Excitation wavelengths of 500 or 560 nm were used and emission was measured in the range of 550–800 nm, with a 1 nm step and 0.2 s dwell time.

A Malvern Nano Zetasizer was used to measure the hydrodynamic diameter and zeta potential of NDs in the suspension. Samples were diluted with water (0.1 mg ml⁻¹) and sonicated for 10 minutes prior to the analysis. Images of the dry NDs were obtained with a Hitachi S4800 Scanning Electron Microscope. A Vertex 70 Fourier Transform Infrared (FTIR) Spectrometer was used to examine the functionalization of NDs. A μ-Quant Microplate Reader and a Fluorescence Lifetime Spectrometer (FLS) 1000 (Edinburgh Instruments) were employed to assess the light absorption and emission properties of the ND suspension. For the fluorescence measurements, samples were prepared at a concentration of 0.1 mg ml⁻¹ and analysed using a front-face sample holder, 590 nm emission filter and excitation/emission bandwidths of 0.8–3 nm. Excitation wavelengths of 500 nm was used and emission was measured in the range of 550–800 nm with a 1 nm step and 0.2 s dwell time.