BackgroundRespiratory syncytial virus (RSV) causes severe respiratory infection in infants, children and elderly. Currently, there is no effective vaccine or RSV specific drug for the treatment. However, an antiviral drug ribavirin and palivizumab is prescribed along with symptomatic treatment. RSV detection is important to ensure appropriate treatment of children. Most commonly used detection methods for RSV are DFA, ELISA and Real-time PCR which are expensive and time consuming. Newer approach of plasmonic detection techniques like localized surface plasmon resonance (LSPR) spectroscopy using metallic nanomaterials has gained interest recently. The LSPR spectroscopy is simple and easy than the current biophysical detection techniques like surface-enhanced Raman scattering (SERS) and mass-spectroscopy.ResultsIn this study, we utilized LSPR shifting as an RSV detection method by using an anti-RSV polyclonal antibody conjugated to metallic nanoparticles (Cu, Ag and Au). Nanoparticles were synthesized using alginate as a reducing and stabilizing agent. RSV dose and time dependent LSPR shifting was measured for all three metallic nanoparticles (non-functionalized and functionalized). Specificity of the functionalized nanoparticles for RSV was evaluated in the presence Pseudomonas aeruginosa and adenovirus. We found that functionalized copper nanoparticles were efficient in RSV detection. Functionalized copper and silver nanoparticles were specific for RSV, when tested in the presence of adenovirus and P. aeruginosa, respectively. Limit of detection and limit of quantification values reveal that functionalized copper nanoparticles are superior in comparison with silver and gold nanoparticles.ConclusionsThe study demonstrates successful application of LSPR for RSV detection, and it provides an easy and inexpensive alternative method for the potential development of LSPR-based detection devices.Electronic supplementary materialThe online version of this article (doi:10.1186/s12951-016-0167-z) contains supplementary material, which is available to authorized users.

Polymer–inorganic hybrid Janus nanoparticles (PI‐JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI‐JNPs remains challenging. Herein, the construction of a novel Janus Au–porphyrin polymersome (J‐AuPPS) heterostructure by a facile one‐step photocatalytic synthesis is reported. The near‐field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J‐AuPPS is achieved to enhance its near‐infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improves the energy transfer and energetic charge‐carrier generation. Therefore, J‐AuPPS shows a higher NIR‐activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non‐Janus core–particle Au–PPS nanostructure (28.4%). As a result, J‐AuPPS exhibits excellent dual‐mode (photothermal/photodynamic) antibacterial and anti‐biofilm performance, thereby significantly enhancing the in vivo therapeutic effect in an implant‐associated‐infection rat model. This work is believed to motivate the rational design of advanced hybrid JNPs with desirable NFE effect and further extend their biological applications.

Metallic nanoparticles have been focus of research because of their characteristic properties, specifically the LSPR which can have wide applications in biomedical sciences and engineering. Currently, traditional physical and chemical methods can synthesize these nanoparticles but their disadvantages such as costs, time, effectiveness, and toxicity of precursors provide a wide range of problems for the synthesis of these nanoparticles. Recently, some natural polymers and organic compounds have been used for the synthesis of nanoparticles by green methods. In this study, we synthesize copper, silver, and gold nanoparticles using sodium alginate as reducing and stabilizing agent under microwave irradiation. The LSPR for each system was observed by UV-vis spectroscopy. Particle size distribution and zeta potential demonstrate the size and stability for these nanoparticles. FESEM and TEM microscopies have shown the size and morphology of these systems correlated with UV-vis, particle size distribution, and zeta potential analyses. The study demonstrates a rapid, facile, cheaper, and one-step green method of synthesis for these metallic nanoparticles being an alternative to the conventional methods used for synthesis of metallic nanoparticles.

Heteroatom-doped carbon nitride (CN) materials have shown much potential as metal-free photocatalysts for water splitting. Graphitic phosphorus-linked triazine network (g-PCN) materials are a unique class within this family of materials, but remain difficult to access due to long reaction times annealing at temperatures above 500 °C and often afford ill-understood structures. Here, we reveal a milder, lower temperature approach for the synthesis of catalytically active g-PCN materials through combining a room-temperature mechanochemical reaction of sodium phosphide and cyanuric chloride with brief (1 hour) annealing of the milled material at 300 °C. This rapid, low temperature procedure yields ordered g-PCN catalysts whose layered structure was determined through a combination of magic-angle spinning nuclear magnetic resonance (MAS NMR), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). An excellent level of accuracy to simulated 31P MAS NMR signals and PXRD patterns were obtained for the structure of the synthesized layered phosphorus-linked triazine networks following dispersion-corrected density functional theory (DFT). The mechanochemically-generated g-PCN is a highly effective photocatalyst for the hydrogen evolution reaction, producing 122 µmol H2 h-1 g-1 under broad spectrum irradiation.