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Diatoms biosilica shell, frustule, is substitute biostructures to mesoporous silica particles, which possesses their wide surfaces, nano-diameter porosity, mechanical strength, and thermal stability, optical capabilities, and the ability to bind to biomolecules can be used in biosensing applications. In this study, diatom species called Chaetoceros muelleri, was used for the fabrication of the Fe₂O₃-Au-Biosilica magnetic package. After micro-algae cultivation, the synthesis of gold nanoparticles (AuNPs) on silica walls was carried out using the bio-synthesis method, which evaluations have demonstrated the continuous formation of spherical AuNPs on the walls and its surfaces. After this step, the magnetic iron oxide nanoparticles were attached to the silica surface of the diatom, this, in turn, leads to system guiding using a magnetic field. Surface modification of diatoms magnetic complex, by using the APTES, allowed the attachment of fluorescence Rhodamine and the Herceptin antibody (Trastuzumab) to the structure. As well as the attachment of the fabricated system to target cells (SKBR3) was confirmed by fluorescence microscopic analysis. The results of this study indicate the ability and specificity of the diatom silicone shell as a "multipurpose" package for diagnostic and therapeutic activities.

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Total-Internal-Reflection Fluorescence Microscopy (TIRFM) is a useful tool to visualize and record the phenomena that happens below 100 nm thickness of the sample surface. This unique property of TIRFM help to perform a "qualitative" study of cytoskeleton near the cell-substrate contact. Here,   distribution of actin filaments at cell-substrate interface was imaged by a TIRFM set up. Then, staining the actins cytoskeleton of the human melanoma cell and implementing the prism-based total-internal-reflection fluorescence microscope.  A method to "quantify" distribution of fluorophores at cell-substrate contact is proposed.