Search results for "NANOTUBES"

Hydrogen Bonding Donor–Acceptor Carbon Nanostructure

2012

The natural process of photosynthesis is paradigmatic in converting sunlight into energy. This complicated process requires a cascade of energy- and electron-transfer events in a highly organised matrix of electron–donor, electron–acceptor and antennae units and has prompted researchers to emulate it. In fact, energy- and electron-transfer processes play a pivotal role in molecular-scale optoelectronics. In this chapter we compile a number of remarkable examples of noncovalent aggregates formed by the combination of carbon-based electroactive species (fullerenes and carbon nanotubes) hydrogen bonded with a variety of moieties. We will show that: (a) the connection of complementary electroac…

Site-specific halloysite functionalization by polydopamine: A new synthetic route for potential near infrared-activated delivery system

2022

Abstract Halloysite nanotubes (HNTs) represent a versatile core structure for the design of functional nanosystems of biomedical interest. However, the development of selective methodologies for the site-controlled functionalization of the nanotubes at specific sites is not an easy task. This study aims to accomplish a procedure for the site-selective/specific, “pin-point”, functionalization of HNTs with polydopamine (HNTs@PDA). This goal was achieved, at pH 6.5, by exploiting the basicity of ZnO nanoparticles anchored on the HNTs external surface (HNTs@ZnO) to induce a punctual polydopamine polymerization and coating. The morphology and the chemical composition of the nanomaterial was demo…

Near-Infrared Light Responsive Folate Targeted Gold Nanorods for Combined Photothermal-Chemotherapy of Osteosarcoma.

2017

Folate-targeted gold nanorods (GNRs) are proposed as selective theranostic agents for osteosarcoma treatment. An amphiphilic polysaccharide based graft-copolymer (INU-LA-PEG-FA) and an amino derivative of the α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide functionalized with folic acid (PHEA-EDA-FA), have been synthesized to act as coating agents for GNRs. The obtained polymer-coated GNRs were characterized in terms of size, shape, zeta potential, chemical composition, and aqueous stability. They protected the anticancer drug nutlin-3 and were able to deliver it efficiently in different physiological media. The ability of the proposed systems to selectively kill tumor cells was tested on U2OS…

Glucose-triggered release using enzyme-gated mesoporous silica nanoparticles.

2013

[EN] A new gated nanodevice design able to control cargo delivery using glucose as a trigger and cyclodextrin-modified glucose oxidase as a capping agent is reported.

Synthesis and study of new fluorescent probes for optical imaging, Cherenkov imaging and multimodal imaging

2015

The goal of this work was to prepare and study new fluorescent probes, which could give rise to novel optical or Cherenkov imaging agents. The first section of this work describes the synthesis of fluorescent subphthalocyanines and phthalocyanines probes, which possess relevant chemicals groups suitable for optical imaging applications. The optical and physico-chemical properties of the new probes were carefully examined to ensure they comply with the specification of the fluorophores for the desired application. The second part focused on the subsequent development of a few selected probes into real imaging agents. The biovectorisation of subphtalocyanines was achieved upon conjugation of …

Core–Shell Nanorod Columnar Array Combined with Gold Nanoplate–Nanosphere Assemblies Enable Powerful In Situ SERS Detection of Bacteria

2016

Development of a label-free ultrasensitive nanosensor for detection of bacteria is presented. Sensitive assay for Gram-positive bacteria was achieved via electrostatic attraction-guided plasmonic bifacial superstructure/bacteria/columnar array assembled in one step. Dynamic optical hotspots were formed in the hybridized nanoassembly under wet-dry critical state amplifying efficiently the weak vibrational modes of three representative food-borne Gram-positive bacteria, that is, Staphylococcus xylosus, Listeria monocytogenes, and Enterococcus faecium. These three bacteria with highly analogous Raman spectra can be effectively differentiated through droplet wet-dry critical SERS approach combi…

Solid-State Pyrolyses of Metal Phthalocyanines: A Simple Approach towards Nitrogen-Doped CNTs and Metal/Carbon Nanocables

2006

Solid-state pyrolysis of organometallic precursors has emerged as an alternative method for preparing carbon nanostructures such as carbon nanotubes (CNT) and carbon anions. The morphology of the tubes can be controlled by the nature of the precursors and the pyrolysis procedures, and micrometer long nanotubes, composed of metal carbide wires encased in a graphitic sheath. Cobalt phthalocyanine (CoPc) as well as iron phthalocyanine were pyrolyzed at different temperatures to obtain CNTs. HRTEM and energy-dispersion X-Ray analysis disclosed that the core consisted of long, iron-containing single crystals and that the core was fully surrounded by crystallized graphic carbon. Iron-filled carbo…

Synthetic Approaches to Functionalized Chalcogenide Nanotubes

2008

Gold nanoparticles stabilized by modified halloysite nanotubes for catalytic applications

2019

A highly sustainable prototype of a flow system based on gold nanoparticles (4.2 nm) supported on thiol-functionalized halloysite nanotubes (HNTs) was developed for catalytic applications. The catalytic performances were evaluated using the reduction of 4-nitrophenol to 4-aminophenol as a model system. Under the best experimental conditions (0.0001 mol%, 1.97 × 10−8 mg of Au nanoparticles), an impressive apparent turnover frequency value up to 2 204 530 h−1 was achieved and the halloysite-based catalyst showed full recyclability even after ten cycles. The high catalytic activity confirms the importance of the use of HNTs as support for Au nanoparticles that can exert a synergistic effect bo…

Highly Loaded Multi-Walled Carbon Nanotubes Non-Covalently Modified with a Bis-Imidazolium Salt and their Use as Catalyst Supports

2016

The surfaces of multi-walled carbon nanotubes (MWCNTs) were non-covalently modified using two bis-imidazolium dibromide derivatives having phenyl or pyrene groups. Due to the presence of the two pyrene groups the bis(pyren-1-ylmethylimidazolium) dibromide derivative was immobilised at a loading of about 15-16 wt %, whereas only <3 wt % of the phenyl derivative was immobilised. The presence of the two imidazolium cations helped the immobilisation of tetrachloropalladate ions after exchange with bromide ions. Tetrachloropalladate was used as pre-catalyst in several Suzuki-Miyaura carbon-carbon cross-coupling reactions in water or water/ethanol at 50 °C in only 0.1 mol % and compared with the …