Raman Spectroscopy was performed on a confocal micro-Raman spectrometer (Renishaw inVia) with an argon ion laser at an excitation wavelength of 633 nm from 1000 to 3000 cm-1. All scans were taken with x20 lens at 600 l mm-1 grating. Samples for Raman analysis were prepared by deposition of dry samples onto a glass substrate. Field Emission Scanning Electron Microscopy (FESEM, Zeiss Ultra 55 Model) with Energy-Disperse X-Ray Spectroscopy was operated at an accelerating voltage of 2 kV to observe the morphology of GO and the crosslinked GO networks at a magnification of 50000, and at 20 kV for the elemental analysis. High-resolution Transmission Electron Microscopy (HR-TEM) with Scanning Transmission Electron Microscope (STEM) Dark Field Imaging at a magnification of 300000 was performed using a JEOL-TEM 2100F 200 kV electron microscope dispersing the samples with dichloromethane in an ultrasonic bath for ten minutes and subsequent drying at room temperature. The micrographs of the calcium alginate composites were taken on a TSM Tandem scanning confocal microscope (TSM) (Noran Instruments, Middleton, WI, USA) with a Motorized Lab Jack (Thorlabs, LTD.,Ely, UK) in conjunction with an EMCCD camera iXon 885 EM-CCD (electron multiplying charge-coupled device) with iQ capture software (Andor Technology, Northern Ireland, UK). A Jade series differential scanning calorimeter was used to determine the thermal properties and Perkin Elmer Jade series software to process raw data. 10–20mg samples were carefully placed and sealed in aluminium pans (Perkin Elmer). The scans were carried out with reference pan calibrated using Indium49 under a Nitrogen7 atmosphere. The vacuum dried samples were subjected to a cooling scan from room temperature down to -30°C, followed by a heating scan up to 300°C at 10°C/min. These DSC scans were performed twice for each sample to ensure their reproducibility. A Perkin-Elmer DMA-800 dynamic mechanical analyser at a frequency of l Hz was used to determine the temperature dependence of storage modulus (E'), loss modulus (E”), and loss tangent (tan δ) from -50°C to 90°C of the dry samples with a heating rate of 1 K/min. FTIR transmission spectroscopy with a range of 650 to 4000 cm-1 was carried on a Perkin Elmer Spectrum One Fourier Transforms Infrared spectrometer.