Nchv model cantilevers

Free-standing GO membranes were prepared by etching nylon substrates in concentrated hydrochloric acid (Sigma-Aldrich). Subsequently, these free-standing GO films were transferred to microscope glass slides. Atomic force microscopy measurements were carried out using a JPK Nanowizard 3 to calculate the thickness of GO membranes. This instrument is equipped with capacitive sensors to ensure accurate reporting of height, z and x–y lateral distances. Imaging was performed in tapping mode using a Bruker NCHV model cantilevers with diameter 10 nm, with nominal resonant frequencies of 340 Hz, spring constant of 20−80 N m⁻¹. Images were obtained with a set-point force of 1 nN. The cantilever drive frequency was chosen to be 5% smaller than the resonance frequency. The thickness of the GO films were estimated from the height difference between the glass and the GO films from three different positions using a line scan as is shown in Fig. 2i for the membrane with a thickness of 150±15 nm.

Human RBCs from different sources (AbtectcellTM III 3%, Commonwealth Serum Laboratory (CSL) and donor samples obtained from Australian Red Cross Blood Service diluted to 3% in ID CellStab, Bio-Rad Laboratories Pty. Ltd.) were prepared for 3 different conditions. 1) Blank controls were RBCs without any form of incubation. 2) RBCs for temperature control were incubated at 37 °C for 30 minutes without addition of antibodies. 3) RBCs for positive samples were D+ incubated at 37 °C for 30 minutes with 2% for further manufacturing use (FFMU) IgG anti-D for further manufacturing use (FFMU), CSL. Blood smears from the 3 samples were prepared on microscope glass slides and air dried. Glass slides were imaged with a JPK Nanowizard 3 AFM in AC (intermittent contact) mode using Bruker NCHV model cantilevers, which had nominal resonant frequencies of 320 kHz and spring constants of 42 N/m. Images were obtained with a set-point force of <1 nN. Scans of 1 μm × 1 μm on random regions of the red blood cell surface were performed for the RMS roughness study.

BC composites [BC, BCP (0.5 %), BCX (0.5 %), BCP (0.1 %) X (0.1 %), BCP (0.1 %) X (0.3 %), BCP (0.1 %) X (0.5 %)] were air dried for 3 days after harvesting and rinsing. Intermittent contact (AC) mode was used on a JPK Nanowizard 3 AFM (JPK Instruments, Berlin, Germany) with Bruker NCHV model cantilevers (California, USA). AFM height images were analysed using Scanning Probe Image Processor (SPIP) software (NanoScience, USA). The diameter of the microfibrils were determined using the cross section profile tool which extracts height profiles, wherein the width of the peaks represents the width of the microfibrils as illustrated by Cybulska et al. [24 ]. The mean diameter of microfibrils for each composite was determined from 10 different microfibrils lying on relatively flat surfaces of the BC composites (without large scale features, such as G. xylinus cells) chosen from each of 3 images for each type of sample. The average roughness and root mean square (RMS) roughness were determined by choosing 10 relatively flat areas from each of 3 images for every type of BC composite.