Energy dispersive x ray spectroscopy eds detector

Gelatin solutions of 2 and 4% (weight %) were prepared in PBS, mixed and vortexed with aqueous suspensions of SiNPs to obtain homogeneously cross-linked gels. All the modulus measurements were carried out for strain sweep (1–10% strain) at a fixed frequency of 0.1 Hz, at 37 ° C using a rheometer (Anton Paar) equipped with 50 mm flat-plate geometry and a gap of 50 µm. For scanning electron microscopy (SEM), samples were freeze dried and sliced into transverse sections by razor slitting. The sections were then sputter coated with Pt/Pd to provide conductivity. All the images were captured using Quanta 600 (FEI) at 20 kV equipped with energy-dispersive X-ray spectroscopy (EDS) detector (Oxford Instruments). The recorded EDS spectra were further analyzed by INCA software (Oxford Instruments) to confirm the presence of elements. For transmission electron microscopy (TEM) imaging of the SiNPs, approximately 5 µL volume of SiNPs in water was drop-casted onto a carbon-coated copper grid and air-dried. The images were captured under 200 keV voltage using JEOL JEM-2010 instrument (Japan). Bacterial endotoxin studies were performed using the US Food and Drug Administration (FDA) guidelines using limulus amebocyte lysate (LAL) assay [46 (link)].