A spinnable coating capable of releasing metal species to a broth of living organisms in a controlled manner is an extremely interesting material for a number of biotechnological applications. Polymer/metal nanocomposites are a viable choice but very little is known about their biological properties. Here, a polymer based nanocomposite loading stabilized copper nanoparticles is proposed as a biostatic coating and systematic correlations between material properties and biological effects are established. Experimental proof of the nanocomposite capability to release metal species in a controlled manner and eventually to slow or even inhibit the growth of living organisms, such as fungi and other pathogenic microorganisms, are provided. The biostatic activity is correlated to the nanoparticle loading that controls the release of copper species, independently evaluated by means of electro-thermal atomic absorption spectroscopy. Insights into the understanding of the controlled releasing process, involving CuO dissolution through the nanoclusters stabilizing layer, are also proposed.

Since 2004, we have been developing nanomaterials with antimicrobial properties, the so-called nanoantimicrobials. When the coronavirus disease 2019 (COVID-19) emerged, we started investigating new and challenging routes to nanoantivirals. The two fields have some important points of contact. We would like to share with the readership our vision of the role a (nano)materials scientist can play in the fight against the COVID-19 pandemic. As researchers specifically working on surfaces and nanomaterials, in this letter we underline the importance of nanomaterial-based technological solutions in several aspects of the fight against the virus. While great resources are understandably being dedicated to treatment and diagnosis, more efforts could be dedicated to limit the virus spread. Increasing the efficacy of personal protection equipment, developing synergistic antiviral coatings, are only two of the cases discussed. This is not the first nor the last pandemic: our nanomaterials community may offer several technological solutions to challenge the ongoing and future global health emergencies. Readers' feedback and suggestions are warmly encouraged.

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Organic bioelectronic sensors are gaining momentum as they can combine high-performance sensing level with flexible large-area processable materials. This opens to potentially highly powerful sensing systems for point-of-care health monitoring and diagnostics at low cost. Prominent to detect biochemical recognition events, are electrolyte-gated organic field-effect transistors (EGOFETs) and organic electrochemical transistors (OECTs) as they are easily fabricated and operated. EGOFETs are recently shown to be capable of labelfree single-molecule detections, even in serum. This progress report aims to provide a critical perspective through a selected overview of the literature on both EGOFET and OECT biosensors. Attention is paid to correctly attribute them to the potentiometric and amperometric biosensor categories, which is important to set the right conditions for quantification purposes. Moreover, to deepen the understanding of the sensing mechanisms, with the support of unpublished data, focus is put on two among the most critical aspects, namely, the capacitance interplay and the role of Faradaic currents. The final aim is to provide a rationale of the functional mechanisms encompassing both EGOFET and OECT sensors, to improve materials and devices' designs taking advantage of the processes that enhance the sensing response enabling the extremely highperformance level resulting in ultimate sensitivity, selectivity, and fast response.