We demonstrate that anisotropic semiconductor nanocrystals display localized surface plasmon resonances that are dependent on the nanocrystal shape and cover a broad spectral region in the near-IR wavelengths. In-plane and out-of-plane dipolar resonances were observed for colloidal dispersions of Cu(2-x)S nanodisks, and the wavelengths of these resonances are in good agreement with calculations carried out in the electrostatic limit. The wavelength, line shape, and relative intensities of these plasmon bands can be tuned during the synthetic process by controlling the geometric aspect ratio of the disk or using a postsynthetic thermal-processing step to increase the free carrier densities.
Bimetallic nanoparticles (NPs) are known to exhibit enhanced optical and catalytic properties that can be optimized by tailoring NP composition, size, and morphology. Galvanic deposition of a second metal onto a primary metal NP template is a versatile method for fabricating bimetallic NPs using a scalable, solution-based synthesis. We demonstrate that the galvanic displacement reaction pathway can be controlled through appropriate surface modification of the NP template. To synthesize bimetallic Au-Ag NPs, we used colloidal Ag NPs modified by layer-by-layer (LBL) assembled polyelectrolyte layers to template the reduction of HAuCl(4). NPs terminated with positively and negatively charged polyelectrolytes yield highly contrasting morphologies and Au surface concentrations. We propose that these charged surface layers control galvanic charge transfer by controlling nucleation and diffusion at the deposition front. This surface-directed synthetic strategy can be advantageously used to tailor both overall NP morphology and Au surface concentrations.
Background
Contact hypersensitivity (CHS) is a murine model used to investigate the role of the immune system in eliciting the skin’s inflammatory response to small compounds called haptens. Although many studies have identified the immune cell subsets involved in mediating the inflammatory response, the spatiotemporal behaviour of these immune cells in vivo is not well-defined.
Aim
The aim of this project is to delineate the spatiotemporal behaviour of numerous innate immune cell subsets during the different phases of CHS. In particular, we will be focusing on the behaviour of dermal dendritic cells (dDCs), perivascular macrophages (PVM) and mast cells.
Methods
Utilising the technique of intravital multiphoton microscopy, we have observed changes in the behaviour of the above-mentioned immune cell subsets following sensitisation with the hapten 2,4-dinitro-1-fluorobenzene (DNFB).
Results
Intravital imaging of homeostatic ear skin identified three migratory behaviours exhibited by dDCs as they interact with sessile PVM. Immediately post-sensitisation, a significant increase in the formation of stable cellular interactions were observed between dDCs and PVM. However, following mast cell degranulation, granule uptake by PVM resulted in the dissociation of these stable interactions. Hence, implying the potential egress of dDCs to the draining lymph nodes for T cell priming.
Conclusion
Our findings have identified a novel cellular mechanism involved in mediating the sensitisation phase of CHS. Further investigation into the molecular mechanisms regulating these cellular events will potentiate the identification of possible therapeutic targets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.