Distribution Of Gold Nanorods Research Articles

Tweezing and manipulating the distribution of gold nanorods (GNRs) on a tapered optical fiber to develop a plasmonic structure

A fiber-based plasmonic structure, called a fiber probe, was developed using gold nanorods (GNRs). The distribution of gold nanorods was manipulated using different wavelengths by the phenomenon called optical tweezing. The GNRs are deposited on a tapered fiber surface, which was prepared by etching a multimode fiber. We investigated the physical characteristics of the tapered fiber on the distribution of GNRs. The experimental results based on the developed plasmonic structure as a surface-enhanced raman spectroscopy (SERS) substrate for the detection of graphite and R6G has been reported. The plasmonic structure was also characterized optically.

Synchrotron-based X-ray fluorescence study of gold nanorods and skin elements distribution into excised human skin layers.

Understanding the distribution of nanoparticles in skin layers is fundamentally important and essential for developing nanoparticle-based dermal drug delivery systems. In the present study, we provide insights into the distribution of gold nanorods (GNRs) functionalized with hydrophobic or hydrophilic ligands in human skin layers using synchrotron X-ray fluorescence (SR-XRF) spectroscopy, confocal microscopy, and transmission electron microscopy. The results confirmed the important role that the surface chemistry of GNRs plays in their penetration into the skin; the GNRs coated with polyethylene glycol were distributed into the skin layers to a greater extent than the GNRs coated with hydrophobic polystyrene thiol. In addition, SR-XRF analysis revealed that the spatial distribution of endogenous elements (phosphorus and sulfur) in skin layers demonstrated a significant "anti-correlation" relationship with that of GNRs. These results suggest possible association (via adsorption) between the GNRs and these two elements localized in skin, which can be valuable for understanding the penetration mechanism of gold nanoparticles into the skin.

Plasmonic Photothermal Therapy of Transplanted Tumors in Rats at Multiple Intravenous Injection of Gold Nanorods

The aim of this study was to evaluate the morphological changes in tumor tissue in rats with transplanted liver cancer PC-1 after repeated intravenous (IV) administration of gold nanorods (GNRs) and plasmonic photothermal therapy (PPT). GNRs with aspect ratio 4.1 and plasmonic peak at 810 nm were functionalized with thiolated polyethylene glycol and IV administered at a single dose 0.4 mg of Au and by repeated injection of the same dose for 2 and 3 days (the total doses were 0.8 and 1.2 mg of Au, respectively). One day after the last IV injection of GNRs, the tumors were irradiated by an 808-nm NIR diode laser at a power density 2.3 W/cm2 during 15 min. The withdrawal of the animals from the experiment and sampling of the tissues for morphological study and GNR distribution were performed 24 h after the PPT. Repeated IV administration of GNRs in tumor-bearing rats resulted in the highest accumulation of nanoparticles in both liver and spleen tissues. After triplicate IV injection of GNRs, they accumulated in the tumor and related PPT effects were comparable with those observed after direct intratumoral injection of the single GNR dose.

Original Covalent Approach for Gold Nanorods Immobilization onto Acid-Terminated-Cysteamine Self-Assembled Monolayers for FT-SPR Biosensor Applications

In this paper, we report an original method to immobilize gold nanorods onto mixed self-assembled monolayers (SAMs) of Mercaptoundecanoic Acid (MUA), Mercaptohexanol (MOH) and cysteamine (CYS) onto planar gold surface. Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed a remarkable shape and size narrow distribution on well functionalized gold surfaces, as well as a tendency to form linear assemblies after immobilization. The results highlight the good distribution of gold nanorods with an average length of 32.6 ± 0.9 nm and width of 13 ± 1.8 nm, the simplicity of the immobilization procedure of gold nanorods and the interest of using them as labels to enhance the sensitivity of FT-SPR-based sensors. gold nanostructured surface FT-SPR measurements of biorecognition using gold nanorods immobilized onto gold surfaces were performed at various prostatic antigen specific (PSA) concentrations, from 5 mg/L to 0.5 mg/L reaching a system sensitivity of 37 ± 2 cm-1/ mgL-1.

More efficient NIR photothermal therapeutic effect from intracellular heating modality than extracellular heating modality: an in vitro study

In this study, efforts were placed in giving some in vitro key clues to the question on which is more efficient for the cancer hyperthermia between intracellular and extracellular modalities. Near infrared (NIR) photothermal responsive gold nanorods (GNRs) were adopted to cause cellular thermolysis either from inside or outside of cells. GNRs were synthesized with the size of 30.4 nm (in length) × 8.4 nm (in width). Demonstrated by ICP-MS (inductively coupled plasmon mass spectroscopy), UV–Vis spectroscopy and transmission electron microscopy analyses, various cell uptake doses of nanoparticles were differentiated due to different molecular designs on GNRs surfaces and different types of cells chosen (three cancer cell lines and three normal ones). Under our continuous wavelengths (CW) NIR irradiation, it resulted that the cells which internalized GNRs died faster than the cells surrounded by GNRs. Furthermore, fluorescent images and flow cytometry data also showed that the NIR photothermal therapeutic effect was greater when the amount of internalized GNRs per cell was larger. Generally speaking, the GNRs assisted intracellular hyperthermia exhibited more precise and efficient control on the selective cancer ablation. To a larger degree, such a relationship between GNRs distribution and hyperthermia efficiency might be applied to wider spectra of cell types and heat-producing nanoparticles, which provided a promise for future cancer thermal therapeutic designs.