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Abstract Electrodes functionalised with weak electroactive microorganisms offer a viable alternative to conventional chemical sensors for detecting priority pollutants in bioremediation processes. Biofilm-based biosensors have been proposed for this purpose. However, biofilm formation and maturation require 24–48 h, and the microstructure and coverage of the electrode surface cannot be controlled, leading to poorly reproducible signal and sensitivity. Alternatively, semiconductive biocompatible coatings can be used for viable cell immobilization, achieving reproducible coverage and resulting in a stable biosensor response. In this work, we use a polydopamine (PDA)-based coating to immobilize Saccharomyces cerevisiae yeast viable cells on carbon screen printed electrodes (SPE) for Cu(II) detection, with potassium ferricyanide (K3[Fe (CN)6]) as a redox mediator. Under these conditions, the current output correlates with Cu (II) concentration, reaching a limit of detection of 2.2 µM, as calculated from the chronoamperometric response. The bioelectrochemical results are supported by standard viability assays, microscopy, and electrochemical impedance spectroscopy. The PDA coatings can be functionalised with different mutant strains, thus expanding the toolbox for biosensor design in bioremediation.

The low-cost and early monitoring of metal ion contaminants is paramount to prevent widespread contamination of water environments. Self-powered microbial electrochemical sensors represent an interesting approach to achieving this goal. Purple non-sulfur bacteria have a versatile metabolism and a well-characterized photosynthetic system, making them an ideal candidate for developing biohybrid technologies. In this work, we report the use of these bacteria in biophotoelectrodes to develop self-powered monitoring systems for two common pollutants, NiCl2 and CuSO4. The microbial biophotoelectrode was obtained on a homemade poly-hydroxybutyrate-carbon nanofibers electrode modified with a redox-adhesive polydopamine matrix-based entrapping the purple bacterium Rhodobacter capsulatus. The presence of 500 μM NiCl2 resulted in a 60 % decrease in current density, while the simultaneous presence of 100 μM NiCl2 and 100 mM CuSO4 led to an 83 % current inhibition. Given the implementation of the biophotoelectrode in the field, the biohybrid system was tested in a complex matrix containing beer, demonstrating the promising ability of the photoelectrochemical system to act as an efficient biosensor in complex solutions. Finally, the biohybrid electrode was coupled to a cathode performing oxygen reduction, which allowed obtaining a self-powered monitoring system, paving the way for the future implementation of a low-cost monitoring system for widespread metal ions contaminant monitoring.

Abstract Invited for this issue's Front Cover is the international collaborative team with researchers from Università degli Studi di Bari “Aldo Moro” (Italy), São Paulo State University (UNESP, Brasil), and Consiglio Nazionale delle Ricerche (Italy). The cover picture shows purple bacterial cells that hit, or miss, their “target electrode” with photo‐induced electrons depending on the concentration of dinitrophenol at which they are exposed. Under low dinitrophenol concentration, the electrons can reach the target, while under high dinitrophenol concentrations the electrons are diverted away from the electrode. Read the full text of the Research Article at 10.1002/celc.202300013.

The development of bioelectrochemical systems requires careful selection of both their biotic and abiotic components to obtain sustainable devices. Herein, we report a biophotoelectrode obtained with polyhydroxybutyrate (PHB), a biopolymer, which purple non-sulphur bacteria produce as an energy stock under specific environmental conditions. The electrode was obtained by casting a mixture composed of PHB and carbon fibers in a 3:2 mass ratio. Following, the composite material was modified with polydopamine and thermally treated to obtain a hydrophilic electrode with improved electrochemical behavior. The bio-based electrode was tested with metabolically active cells of Rhodobacter capsulatus embedded in a biohybrid matrix of polydopamine. The system achieved enhanced catalytic activity under illumination, with an 18-fold increase in photocurrent production compared to biophotoelectrodes based on glassy carbon, reaching a current density of 12 ± 3 μ A cm−2, after 30 min of light exposure at +0.32 V. The presented biocompatible electrode provides a sustainable alternative to metal-based and critical raw material-based electrodes for bioelectrochemical systems. [ABSTRACT FROM AUTHOR]

11 Saisho Y. Use of diabetes treatment satisfaction questionnaire in diabetes care: importance of patient-reported outcomes. Patient enrolment might not be fully representative of the general population of elderly adults with T1D because of the requirement for insulin pump therapy. Keywords: continuous glucose monitoring; insulin pump therapy; real-world evidence; type 1 diabetes EN continuous glucose monitoring insulin pump therapy real-world evidence type 1 diabetes 2034 2037 4 06/06/23 20230701 NES 230701 BACKGROUND The advancements in diabetes care leading to longer life expectancy have increased the population of older adults with type 1 diabetes (T1D).[1] In this population, the management of diabetes is often challenging because of the presence of possible cognitive impairment, co-morbidities and specific diet requirements. All-cause mortality trends in a large population-based cohort with long-standing childhood-onset type 1 diabetes: the Allegheny County type 1 diabetes registry. [Extracted from the article]