Self-assembly of noble metal-free graphene–copper plasmonic metasurfaces

The strong light confinement and near field enhancement by metallic scatters enabled the development of a large family of plasmonic-based technologies, including broadly used gold metasurfaces. Despite progress, the engineering of non-precious metal plasmonic devices remains challenging, due to the limited chemical stability of most nanostructured metals. Here, we report the preparation of earth-abundant plasmonic metasurfaces by the engineering of copper-graphene nano-resonators, and their use as localized surface plasmon resonance (LSPR) sensors. We achieve the large-scale self-assembly of Cu nanocrystals, featuring a protective graphene film, by one-step reduction of CuO nanoparticle networks in a hydrocarbon-containing atmosphere. Microscopic and spectroscopic investigations reveal that coalescence and reduction of the CuO nanoparticles during graphene growth result in the formation of graphene-encapsulated metallic Cu nano-islands (NIs). These Cu-graphene metasurfaces can detect down to 1% concentrations of toluene gas at room temperature, displaying a reproducible and rapid LSPR shift of 0.2 nm. Finite-difference time-domain (FDTD) simulation and structural characterization reveal that the graphene layer significantly improves the Cu crystals’ long-term stability, leading to a prolonged LSPR performance over periods of three months. These insights provide promising directions for the development of earth-abundant plasmonic materials with applications ranging from biosensing to photo-catalysis and other optoelectronic devices.</p

Inclusion of Pregnant and Breastfeeding Women in Research – Efforts and Initiatives

Pregnant and breastfeeding women have been rendered therapeutic orphans as they have been historically excluded from clinical trials. Labelling for most approved drugs does not provide information about safety and efficacy during pregnancy. This lack of data is mainly due to ethico‐legal challenges that have remained entrenched in the post‐diethylstilbestrol and thalidomide era, and that have led to pregnancy being viewed in the clinical trial setting primarily through a pharmacovigilance lens. Policy considerations that encourage and/or require the inclusion of pregnant or lactating women in clinical trials may address the current lack of available information. However, there are additional pragmatic strategies, such the employment of pharmacometric tools and the introduction of innovative clinical trial designs, which could improve knowledge about the safety and efficacy of medication use during pregnancy and lactation. This paper provides a broad overview of the pharmacoepidemiology of drugs used during pregnancy and lactation, and offers recommendations for regulators and researchers in academia and industry to increase the available pharmacokinetic and ‐dynamic understanding of medication use in pregnancy