Gold and Silver Nanowires for Fluorescence Enhancement

25 page(s

Propagating Surface Plasmons and Dispersion Relations for Nanoscale Multilayer Metallic-Dielectric Films

22 page(s

Potential Use of Quantum Dots in Flow Cytometry

QDs may offer significant advantages in environmental and bead-based applications where the target cells need to be discriminated above background fluorescence. We have examined the possible applications of QDs for flow cytometric measurements (FCM) by studying their excitation - emission spectra and their binding to paramagnetic beads. We labelled beads with either QDs or a commonly-used fluorochrome (FITC) and studied their fluorescence intensity by FCM. Flow cytometric comparisons indicated that the minimum fluorophore concentration required for detection of QDs above autofluorescent background was 100-fold less than for FITC

Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals

The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials. We experimentally verify the co-existence and different roles of oleate anions (OA-) and molecules (OAH) in the crystal formation. We identify that the control over the ratio of OA- to OAH can be used to directionally inhibit, promote or etch the crystallographic facets of the nanoparticles. This control enables selective grafting of shells with complex morphologies grown over nanocrystal cores, thus allowing the fabrication of a diverse library of monodisperse sub-50 nm nanoparticles. With such programmable additive and subtractive engineering a variety of three-dimensional shapes can be implemented using a bottom-up scalable approach

Acute stress induces the rapid and transient induction of caspase-1, gasdermin D and release of constitutive IL-1 protein in dorsal hippocampus

The proinflammatory cytokine interleukin (IL)-1 plays a pivotal role in the behavioral manifestations (i.e., sickness) of the stress response. Indeed, exposure to acute and chronic stressors induces the expression of IL-1 in stress-sensitive brain regions. Thus, it is typically presumed that exposure to stressors induces the extracellular release of IL-1 in the brain parenchyma. However, this stress-evoked neuroimmune phenomenon has not been directly demonstrated nor has the cellular process of IL-1 release into the extracellular milieu been characterized in brain. This cellular process involves a form of inflammatory cell death, termed pyroptosis, which involves: 1) activation of caspase-1, 2) caspase-1 maturation of IL-1, 3) caspase-1 cleavage of gasdermin D (GSDMD), and 4) GSDMD-induced permeability of the cell membrane through which IL-1 is released into the extracellular space. Thus, the present study examined whether stress induces the extra-cellular release of IL-1 and engages the above cellular process in mediating IL-1 release in the brain. Male Sprague-Dawley rats were exposed to inescapable tailshock (IS). IL-1 extra-cellular release, caspase-1 activity and cleavage of GSDMD were measured in dorsal hippocampus. We found that exposure to IS induced a transient increase in the release of IL-1 into the extracellular space immediately after termination of the stressor. IS also induced a transient increase in caspase-1 activity prior to IL-1 release, while activation of GSDMD was observed immediately after termination of the stressor. IS also increased mRNA and protein expression of the ESCRTIII protein CHMP4B, which is involved in cellular repair. The present results suggest that exposure to an acute stressor induces the hallmarks of pyroptosis in brain, which might serve as a key cellular process involved in the release of IL-1 into the extracellular milieu of the brain parenchyma.</p

The Australian research network for fluorescence applications in biotechnology and life sciences

[Abstract]: A new research network has been established to bring together the leading Australian researchers and developers of fluorescence technologies. The Australian Research Network for Fluorescence Applications in Biotechnology and Life Sciences (FABLS) was designed to inspire and coordinate multi-disciplinary research programs relating to applications of fluorescence. The Australian Government is providing the Network with $2 million in joint funding (2004-2009) through the Australian Research Council (ARC) and the National Health and Medical Research Council (NH&MRC). FABLS currently integrates activities of over 70 members from 40 organisations, including 16 private sector companies. While the Network is based in Australia, current membership also includes researchers from the USA, Germany, India, New Zealand and Russia. Through its focus on academic-industry collaboration, the Network will help turn basic scientific discoveries into commercial outcomes. Examples of cross-disciplinary projects undertaken by Network members include the development of time-resolved fluorescence instrumentation for ultra-sensitive microbial screening, laser-based rapid biochemical assays to recognise heart attack; extraction of commercially significant fluorescent proteins native to Australian reef corals; and the search for specific microorganisms in complex environments such as industrial waste using high level multiplex fluorescent probes. The Network aims to foster national and international collaborations and invites researchers from around the globe to consider participating in its activities. For further information, visit us at http://www.physics.mq.edu.au/research/fluoronet/

Fluorescence applications in biotechnology and life sciences

367 page(s

Metallic Nanomaterials for Sensitivity Enhancement of Fluorescence Detection

Utrasensitive detection of trace analytes by fluorescence benefits forfluorescence amplifying substrates. We review here our recent work concerned withunderstanding of enhancement mechanisms and formation of three such substrates: silverfractals, silver coated gold nanoparticles deposited on glass and fluorescence enhancinggold colloids