A bistren cryptand with a remote thioether function: Cu(ii) complexation in solution and on the surface of gold nanostars

A di-copper(ii) complex is formed in a bis-tren cage featuring a thioether function, capable of grafting on a monolayer of gold nanostars

Status of faecal pollution in ports: A basin-wide investigation in the Adriatic Sea

Ports are subject to a variety of anthropogenic impacts, and there is mounting evidence of faecal contamination through several routes. Yet, little is known about pollution in ports by faecal indicator bacteria (FIB). FIB spatio-temporal dynamics were assessed in 12 ports of the Adriatic Sea, a semi-enclosed basin under strong anthropogenic pressure, and their relationships with environmental variables were explored to gain insight into pollution sources. FIB were abundant in ports, often more so than in adjacent areas ; their abundance patterns were related to salinity, oxygen, and nutrient levels. In addition, a molecular method, quantitative (q)PCR, was used to quantify FIB. qPCR enabled faster FIB determination and water quality monitoring that culture-based methods. These data provide robust baseline evidence of faecal contamination in ports and can be used to improve the management of routine port activities (dredging and ballast water exchange), having potential to spread pathogens in the sea

Recombinant nanobodies as cheap and customizable reagents for unicellular algae detection

At the present, the identification of planktonic species in coastal water mainly relies on light microscopy observations. This kind of analyses is performed by highly trained personnel, requires lab equipment and long processing time. High-throughput and easy-to-perform methods are instead highly needed for routine costal and ballast water monitoring. Immuno-reagents are widely employed in the medical field for routine diagnostics, where they provide the necessary sensitivity and specificity, as for example for cancer subtype characterization. Reagents of similar grade are so far not widely available for both diagnostics and basic research of microalgae. We describe the first successful isolation of a single-domain antibody (nanobody or VHH) from a pre-immune library, its engineering into application-ready reagents, and its inexpensive production as recombinant fusion protein. Alexandrium minutum was chosen as a model organism to test the feasibility of the procedure. The procedure foresees the panning of a pre-immune phage library of VHHs that was used for in vitro selection against directly the target cells. Monoclonal nanobodies specific for A. minutum cells were identified and optimized for recombinant production as fusion with fluorescent proteins in bacterial hosts. Such fluorescently-tagged VHHs were validated by immunofluorescence and cytofluorimetry for their selectivity by testing unicellular algal species that can be found in the same environment of A. minutum. Two nanobodies were found to be highly specific for the target cells, were able to bind also cysts of A. minutum and they gave no cross-reaction, even for a not-toxic strain of the closely related A. tamutum. Different tags can be then fused to the selected nanobodies and used instead of the fluorescent proteins to obtain a reagent immediately applicable to further techniques, such as cell Enzyme Linked Immuno Sorbent Assay (ELISA) or biosensor surface functionalization. The newly produced reagents can be applied for direct whole-cell detection in seawater, bypassing the need of cell processing required for DNA or RNA diagnostics, and can be used for both alive and fixed cells, guaranteeing the possibility to check old samples and to perform confirmatory morphological studies

A gold nanoparticle chemically modified gold electrode for the determination of surfactants

A chemically modified electrode (CME) bearing gold nanoparticles assembled onto a gold electrode via a 1,4-benzenedimethanethiol SAM bridge has been successfully employed for the determination of surfactants in solution, using a redox probe and exploiting the tendency of surfactants to be adhere to the high-energy nanoparticles' surfac

Photothermal effect of gold nanostar patterns inkjet-printed on coated paper substrates with different permeability

Inkjet printing of spherical gold nanoparticles is widely applied in the fabrication of analytical and diagnostics tools. These methods could be extended to non-spherical gold nanoparticles that can efficiently release heat locally when irradiated in the near infrared (NIR) wavelength region, due to localized surface plasmon resonance (LSPR). However, this promising application requires the ability to maintain high efficiency and tunability of the NIR LSPR of the printed nanoparticles. In this study stable inks containing PEGylated gold nanostars (GNS) were fabricated and successfully inkjet-printed onto differently coated paper substrates with different porosity and permeability. A pronounced photothermal effect was observed under NIR excitation of LSPR of the printed GNS patterns even at low laser intensities. It was found that beside the direct role of the laser intensity, this effect depends appreciably on the printing parameters, such as drop density (delta, drops/mm(2)) and number of printed layers, and, critically, on the permeability of the coated paper substrates. These results will promote the development of GNS-based printed platforms for local photothermal therapy

Photothermal effect of gold nanostars inkjet-printed on coated paper substrate under near-infrared irradiation

The research and development of personalized medical treatments is increasing steadily fostered by its large societal impact. The ability of non-spherical gold nanoparticles to locally and efficiently release heat when irradiated in Near Infrared (NIR) wavelength region is a promising tool for photothermal medical therapies. In the present work, stable inks containing PEGylated gold nanostars (GNS) were obtained and inkjet-printed on a pigment coated paper substrate. Significant photothermal effect of the printed patterns was observed under Near Infrared (NIR) excitation of the Localized Surface Plasmon Resonance (LSPR) of the GNS. These preliminary results support, in perspective, the application of printed GNS patterns for thermal medical treatments either by direct localized heating, or by temperature triggered drug releas