Au nanoparticles AuNPs

Aliquat 336 is a commercially available extractant, extensively applied as a carrier in PlMs, which also has plasticizing properties. For this reason, it is frequently used in the manufacturing of PlMs without the addition of a separate plasticizer [17,18], Aliquat 336-based PlMs have been applied to the extraction and/or transport of anionic complexes of mainly heavy metals (e.g., As(V), Au(lll), Cd(ll), Co(ll), Cr(Vl), Cu(ll), Ni(ll), Pd(ll), Pt(lV), Re(Vll)), common anions (e.g., 1 , SCN ), and organic compounds (e.g., small saccharides, amino acids, lactic acid, thiourea) [2,3], Moreover, it has been recently employed in a PVC-based template for the preparation of Au nanoparticles (AuNPs). The nanoparticles were formed either in the bulk of the PIM or as a layer on the PIM surface by loading the membrane with AuClJ by anion-exchange, followed by in situ reduction with BH4 [19,20] or EDTA [21]. Capriquat is another liquid anion-exchanger similar in composition to Aliquat 336 with the major component being trioctylmethylammonium (TOMA) chloride [22]. 

The samples were modified in direct (glow, diode) Ar plasma on Balzers SCD 050 device under the conditions presented in 2.3.1. Immediately after the plasma treatment the samples were inserted into water solution (2 wt. %) of 2-mercaptoethanol (ME), methanol solution (5.10 mol/dm ) of biphenyl-4,4 -dithiol (BPD) or into water solution (2 wt.%) of cysteamine (CYST) for 24 hours. To coat the polymers with the gold nanoobjects the plasma treated pol)rmers with grafted thiols were immersed for 24 hours into freshly prepared colloidal citrate stabilized solution of Au nanoparticles (AuNPs), [44,46] or Au nanorods (AuNR), 0.1 mol/dm water solution of cetyltrimethylammonium bromide). 

Au nanomaterials are the most typical metal photothermal agents, and their LSPR is closely related to their shapes and structures. Currently, several Au nanomaterials with different shapes have been well developed as excellent photothermal agents, including Au nanoparticles (AuNPs), Au nanorods (AuNRs), Au nanoshells (AuNSs), and Au nanocages (AuNCs). 

Figure 7 shows an example of SEM images of Au nanoparticles (AuNPs) on glassy carbon plate before (a) and after polymerization of Ni tetrasulfo phthalo-cyanine (NiTSPc) (b) [35]. Figure 7a shows that the AuNPs are well distributed across the glassy plate surface. The SEM image of poly-NiTSPc/AuNPs (Fig. 7b) suggests that AuNPs have not been completely covered by the NiTSPc layer, since there are still some white spots (though reduced in number) compared to Fig. 7a. It is also possible that poly-NiTSPc occupies the empty areas not covered by AuNPs in Fig. 7b.

Au nanoparticle (AuNP) electrodes prepared through various other deposition strategies have been extensively used for protein voltammetry and in electrochemical biosensing applica-tions. ° ° Electrodes with layers of HRP-modified AuNPs (prepared through covalent modification, self-assembly, or layer-by-layer techniques) have been shown to exhibit electrocatalytic activity toward the reduction of H2O2 through direct electron transfer between electrode and enzyme redox... 

Figure 11. Zeta potential determined by SurPASS of pristine (pristine) and modified (A) PET and (B) PTFE. The polymer foils were plasma treafed (plasma), plasma treated and grafted with (i) thiols (biphenyldithiol-BPD, cysteamine-CYST and mercaptoethanol-ME) and then (ii) grafted with Au nanoobjects (nanoparticles-AuNP and nanorods-AuNR).

The synthesis of molecularly imprinted Au nanoparticle composite (Scheme 1.7) was developed by Frasconi et al. AuNPs were functionalized with thioaniline and mercaptophenylboronic acid, and electropolymerization was carried out in the presence of antibiotics such as streptomycin (35). After removal of the template antibiotics, sensing ability towards the antibiotics were evaluated by means of SPR. It was found that the detection limit... 

Apart from CNTs several nanomaterials were used to modify electrode surfaces. Fan and co-workers improved the enzyme-modified electrode through Au nanoparticles/silicon nanowires (AuNPs/Si-NWs) coated on glassy carbon electrodes. This sensor showed a rapid response towards the substrate acetylcholine in the concentration range of 1.0 pM to 1.0 mM. This electrode could detect as low as 8 ng dichlorvos. 

The third class of AuNPs-dendrimer nanomaterials is Nanoparticle Cored Dendrimers (NCDs). The first report on this topic describes a new strategy in which Frechet-type dendrons with a single thiol group at the focal point were used as a surface stabilizer of Au NPs. These dendronized Au NPs were synthesized using a modification of the two-phase Brust-Schiffrin method, giving rise to highly stable and very monodisperse Au NPs of small size (about 2.4—3.1 nm) [129] (Figure 3.13). 

An application of biomolecule-nanoparticle hybrid supramolecular assemblies is the sensitive detection of p53, a tumor suppressor protein, by AuNP streptavidin conjugates capped with multiple ferrocene molecules.26 As shown in Figure 8.6, a mixed monolayer of double-stranded DNA and 1-hexanethiol on an Au electrode is used to capture p53, which binds to DNA containing the consensus site sequence. Subsequent conjugation of the captured p53 with biotin allowed for attachment of... 

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