Synthesis,X-Ray Characterizations And Bio-Applications Of Two-Dimensional Based Nanomaterials

Nanotechnology offers a multidisciplinary research platform that covers vast and diverse array from device fabrication to their commercial utilizations.Bionanotechnology focuses on engineering nanomaterials with viable potentials for medical applications.Two-dimensional?2D?nanomaterials are gaining attention as they possess some unique chemical,physical and particularly alterable optical properties for useful photothermal associated bio-applications.Our primary research focus is centered on fabricating dynamic 2D materials with enhanced photothermal efficacy that can be potentially translated into clinical cancer therapy and extensive cryopreservation techniques.In this dissertation,multifunctional 2D nanomaterials?WSe₂?synthesized and intercalated expressed phase engineering from 2H to 1T phase through hydrothermal techniques.Graphene@Fe nanosheets were synthesized using chemical vapor deposition?CVD?procedure.Nanoparticles characterization techniques were carried out with scanning electron microscopy?SEM?,scanning transmission electron microscopy?STEM?and Transmission electron microscopy?TEM?,X-ray diffraction?XRD?,Raman spectroscopy and X-ray Photoelectron Spectroscopy?XPS?and synchrotron delivered X-ray absorption spectroscopy?XAS?The biological applications were accompanied by analytical tests such as laser activated temperature profile,cell culture and MTT assay and relevant in vivo cancer therapy.Ice recrystallization inhibition?IRI?activity was investigated by cryomicroscopy experiment using Linkam FDCS196 cryostage having a digital camera.Hopefully,the results obtained will be suitable for future production of cheap,eco-friendly and bio-safe nanomaterials for photoactive thermal driven cancer therapy and cryopreservation.The main results of this thesis are stated below:?1?We fabricated for the first time,a novel metallic WSe₂ intercalated with polyvinylpyrrolidone?PVP?,resulting in ultrathin homogeneous hybridized nanosheets with highly efficient photothermal ablation of cancer in 4T1 tumor bearing female Balb-B mice.Our systematic characterizations revealed that the obtained nanosheets exhibited high photothermal conversion efficiency with excellent bio-compactibility and physiological stability because of the combined merits of metallic phase of WSe₂ and PVP insertion.Both the analyzed histology of vital organs and in vitro/in vivo tests strongly confirmed the nanosheets as actively effective and biologically safe in tumor cells apoptosis through uni-modal phototherapeutic technique.?2?We synthesize WSe₂-PVP nanosheets as antifreeze agents.The as prepared nanoparticles acted as a spatial source for significant enhancement of heating rates activated by near-infrared laser irradiation enabled ice recrystallization inhibition.Sample characterization by SEM reveals that the nanosheet mophorlogy enhanced the phothermal activities rather than nanoflowers which neccecitated importance of ideal percentage precusors ratio of PVP and WSe₂.XRD analysis further confirms switch in crystal phases that accompanied the aforementioned morphological changes.Raman spectroscopy and HAADF STEM techniques further ascertain the respective ultrathin nature and expected elemental composition of WSe₂-PVP nanosheets.808 nm laser activate a fast heating rate in WSe₂-PVP NSs plunging thermal-mechanical stress in the supercooled vitrification solution,an essential characteristic of antifreeze agents used in cryopreservation.?3?Graphene@Fe nanosheets were facilely synthesized through thermal pyrolysis of glucose,dicyandiamide,and metallic iron salts using chemical vapor deposition?CVD?techniques.TEM and HRTEM images reveal extensively ultrathin and flexible oligolayers with embedded Fe nanoparticles.XRD and XPS spectroscopic patterns further affirm successful fabrication of graphene@Fe nanosheets without impurities.Both temperature profile test and thermal photographic images reveal excellent optical performance of the as-prepared nanomaterials.Finally,graphene@Fe nanosheets demonstrated excellent photothermal activated apotosis of HNE-1 nasopharyngeal cancer cells.