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Super-resolution fluorescence microscopy and Förster Resonance Energy Transfer (FRET) form a well-established family of techniques that has provided unique tools to study the dynamic architecture and functionality of biological systems, as well as to investigate nanomaterials. In the last years, the integration of super-resolution methods with FRET measurements has generated advances in two fronts. On the one hand, FRET-based probes have enhanced super-resolution imaging. On the other, the development of super-resolved FRET imaging methods has allowed the visualization of molecular interaction patterns with higher spatial resolution, less averaging and higher dynamic range. Here, we review these advances and discuss future perspectives, including the possible integration of FRET with next generation super-resolution techniques capable of reaching true molecular-scale spatial resolution.

While colloidal chemistry provides ways to obtain a great variety of nanoparticles, with different shapes, sizes, material composition, and surface functions, their controlled deposition and combination on arbitrary positions of substrates remains a considerable challenge. Over the last ten years, optical printing arose as a versatile method to achieve this purpose for different kinds of nanoparticles. In this article we review the state of the art of optical printing of single nanoparticles, and discuss its strengths, limitations, and future perspectives, by focusing on four main challenges: printing accuracy, resolution, selectivity, and nanoparticles photostability., The following article has been submitted to The Journal of Chemical Physics. After it is published, it will be found at https://aip.scitation.org/journal/jcp

Early career researchers (ECRs) are important stakeholders leading efforts to catalyze systemic change in the conduct and communication of science. Here, we summarize the outputs from a virtual unconventional conference (unconference), which brought together 54 invited experts from 20 countries with extensive experience in ECR initiatives designed to improve science. The event was focused on why ECRs are needed to improve science and the obstacles they face when trying to promote reform. Our discussions also highlighted the additional obstacles that ECRs in countries with limited research funding experience when working to improve the scientific system. We provide the lessons learned from successful ECR-led or ECR-focused initiatives and outline actions that individuals and organizations can take to further support ECRs who are working to improve research culture and practice.

Silicon nanoparticles possess unique size-dependent optical properties due to their strong electric and magnetic resonances in the visible range. However, their widespread application has been limited, in comparison with other (e.g.,metallic) nanoparticles, because their preparation on monodisperse colloids remains challenging. Exploiting the unique properties of Si nanoparticles in nano- and microdevices calls for methods able to sort and organize them from a colloidal suspension onto specific positions of solid substrates with nanometric precision. We demonstrate that surfactant-free silicon nanoparticles of a predefined and narrow (σ < 10 nm) size range can be selectively immobilized on a substrate by optical printing from a polydisperse colloidal suspension. The size selectivity is based on differential optical forces that can be applied on nanoparticles of different sizes by tuning the light wavelength to the size-dependent magnetic dipolar resonance of the nanoparticles.

Fil: Zaza, Maria Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina