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This review article focuses on the latest achievements in the creation of a class of electrotuneable optical metamaterials for switchable mirrors/windows, variable colour mirrors, optical filters, and SERS sensors, based on the voltage-controlled self-assembly of plasmonic nanoparticles at liquid/liquid or solid/liquid electrochemical interfaces. Practically, these experimental systems were navigated by physical theory, the role of which was pivotal in defining the optimal conditions for their operation, but which itself was advanced in feedback with experiments. Progress and problems in the realisation of the demonstrated effects for building the corresponding devices are discussed. To put the main topic of the review in a wider perspective, the article also discusses a few other types of electrovariable metamaterials, as well as some of those that are controlled by chemistry.

The article discusses a 2022 report on tunneling probe fabrication, direct measurement, and switching of single-protein conductance with an external field in solution. Topics covered include bridging of a single streptavidin molecule to two electrodes and measuring single-protein tunneling response, and multiple conductive pathways dependent on the applied bias's magnitude afforded by charge transport through the protein. Also noted is the potential fabrication of protein-based junctions.

Quantum mechanical tunnelling sensors (QMTs) have emerged as a promising technology for next-generation single-molecule detection. Furthermore, QMT sensors can be combined with redox species resulting in repeated oxidation and reduction (redox cycling).. We developed robust QMT probes with electrode gap distances below 2 nm. Using the generator-collector (GC) mode, we verified that redox cycling of the ferrocyanide/ferricyanide (Fe(CN) 6 3-/4- ) couple occurs both in the tunnelling regime and on the electrode surface. Our findings indicated that the current enhancement is affected by both the gap distance and surface modifications of the probes. These QMT probes exhibited remarkable sensitivity, capable of detecting Fe(CN) 6 3-/4- concentrations down to sub-picomolar levels. Utilising this ability to modulate redox reactions, we adapted the QMT probes to serve as electrochemical sensors for detecting viral proteins. By modifying the electrode surfaces, our functionalised QMT probes achieved sub-pM detection limits with high selectivity in biofluids such as nasopharyngeal secretions. These findings highlight the potential of QMT probes to develop into a new class of electrochemical tunnelling sensors, offering significant advancements in biomedical diagnostics., (© 2025 Wiley-VCH GmbH.)

This study introduces a novel, environmentally friendly albumin isolation method using graphene oxide (GO). GO selectively extracts albumin from serum samples, leveraging the unique interactions between GO's oxygen-containing functional groups and serum proteins. This method achieves high purification efficiency without the need for hazardous chemicals. Comprehensive characterization of GO and reduced graphene oxide (rGO) through techniques such as X-ray diffraction (XRD) analysis, Raman spectroscopy, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) confirmed the structural and functional group transformations crucial for protein binding. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry analyses demonstrated over 95% purity of isolated albumin, with minimal contamination from other serum proteins. The developed method, optimized for pH and incubation conditions, showcases a green, cost-effective, and simple alternative for albumin purification, promising broad applicability in biomedical research and clinical applications., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Biocompatible connections between external artificial devices and living organisms show promise for future neuroprosthetics and therapeutics. The study in Science by Zhao and colleagues introduces a cascade-heterogated biphasic gel (HBG) iontronic device, which facilitates electronic-to-multi-ionic signal transduction for abiotic-biotic interfaces. Inspired by neuron signaling, the HBG device demonstrated its biocompatibility by regulating neural activity in biological tissue, paving the way for wearable and implantable devices, including brain-computer interfaces., Competing Interests: Competing interests: The authors declare that they have no competing interests., (Copyright © 2024 Xiaoyi Wang et al.)