Galactose monitoring in individuals allows the prevention of harsh health conditions related to hereditary metabolic diseases like galactosemia. Current methods of galactose detection need development to obtain cheaper, more reliable, and more specific sensors. Enzyme-containing amperometric sensors based on galactose oxidase activity are a promising approach, which can be enhanced by means of their inclusion in a redox polymer coating. This strategy simultaneously allows the immobilization of the biocatalyst to the electroactive surface and hosts the electron shuttling units. An additional deposition of capping polymers prevents external interferences like ascorbic or uric acid as well as biofouling when measuring in physiological fuels. This work studies the protection effect of poly(2-methacryloyloxyethyl phosphorylcholine-co-glycidyl methacrylate (MPC) and polyvinylimidazole-polysulfostyrene (P(VI-SS)) when incorporated in the biosensor design for the detection of galactose in human plasma.

Capacitive humidity sensors typically consist of interdigitated electrodes coated with a dielectric layer sensitive to varying relative humidity levels. Previous studies have investigated different polymeric materials that exhibit changes in conductivity in response to water vapor to design capacitive humidity sensors. However, lipid films like monoolein have not yet been integrated with humidity sensors, nor has the potential use of capacitive sensors for skin hydration measurements been fully explored. This study explores the application of monoolein-coated wireless capacitive sensors for assessing relative humidity and skin hydration, utilizing the sensitive dielectric properties of the monoolein-water system. This sensitivity hinges on the water absorption and release from the surrounding environment. Tested across various humidity levels and temperatures, these novel double functional sensors feature interdigitated electrodes covered with monoolein and show promising potential for wireless detection of skin hydration. The water uptake and rheological behavior of monoolein in response to humidity were evaluated using a quartz crystal microbalance with dissipation monitoring. The findings from these experiments suggest that the capacitance of the system is primarily influenced by the amount of water in the monoolein system, with the lyotropic or physical state of monoolein playing a secondary role. A proof-of-principle demonstration compared the sensor's performance under varying conditions to that of other commercially available skin hydration meters, affirming its effectiveness, reliability, and commercial viability.

Managing blood glucose can affect important clinical outcomes during the intraoperative phase of surgery. However, currently available instruments for glucose monitoring during surgery are few and not optimized for the specific application. Here we report an attempt to exploit an enzymatic sensor in a vein replica that could continuously monitor glucose level in an authentic human bloodstream. First, detailed investigations of the superficial venous systems of volunteers were carried out using ocular and palpating examinations, as well as advanced ultrasound measurements. Second, a tubular glucose-sensitive biosensor mimicking a venous system was designed and tested. Almost ideal linear dependence of current output on glucose concentration in phosphate buffer saline was obtained in the range 2.2-22.0 mM, whereas the dependence in human plasma was less linear. Finally, the developed biosensor was investigated in whole blood under homeostatic conditions. A specific correlation was found between the current output and glucose concentration at the initial stage of the biodevice operation. However, with time, blood coagulation during measurements negatively affected the performance of the biodevice. When the experimental results were remodeled to predict the response without the influence of blood coagulation, the sensor output closely followed the blood glucose level.

An electronic tongue is a powerful analytical instrument based on an array of non-selective chemical sensors with a partial specificity for data gathering and advanced pattern recognition methods for data analysis. Connecting electronic tongues with electrochemical techniques for data collection has led to various applications, mostly within sensing for food quality and environmental monitoring, but also in biomedical research for the analyses of different bioanalytes in human physiological fluids. In this paper, an electronic tongue consisting of six electrodes (viz., gold, platinum, palladium, titanium, iridium, and glassy carbon) was designed and tested in authentic (undiluted, unpretreated) human saliva samples from eight volunteers, collected before and during the COVID-19 pandemic. Investigations of 11 samples using differential pulse voltammetry and a principal component analysis allowed us to distinguish between SARS-CoV-2-free and infected authentic human saliva. This work, as a proof-of-principle demonstration, provides a new perspective for the use of electronic tongues in the field of enzyme-free electrochemical biosensing, highlighting their potential for future applications in non-invasive biomedical analyses.

The lack of culturally and contextually oriented interventions promoting physical activity (PA) has led to increased physical inactivity among women living in disadvantaged neighbourhoods in Sweden. In this study one such intervention informed by community-based participatory research (CBPR) has been evaluated among 34 women from a disadvantaged neighbourhood before and during COVID-19. Health-related quality of life (HRQOL), behavioural and biomedical outcomes were assessed directly prior and post-intervention, followed by evaluations at 6-months and 18-months follow-up during COVID-19. The results revealed that HRQOL, particularly psychological, social, and environmental health significantly increased post-intervention compared to prior to intervention but reversed back at 6-months follow-up. Perceived health satisfaction and environmental health increased at 18-months follow-up during COVID-19. Participation in PA improved post-intervention and at 6-months follow-up. Everyday activities and fruit and vegetable intake continued to increase through all timepoints. Systolic blood pressure significantly decreased post-intervention and 6-months follow-up; blood flow rate increased significantly at all timepoints. Overall, the findings underscores the potential effectiveness of CBPR approaches in promoting and sustaining healthy lifestyles, even during acute situations such as the COVID-19. It may even serve as a future model for promoting health and addressing health disparities in similar groups.

Direct transformation of solar energy into electrical energy by means of biological photosynthesis is considered as an attractive option for sustainable electrical energy production. Thylakoid membranes, the site of photosynthesis, are regarded as a promising biological material for the development of photoelectric biodevices, which produce electrical power consuming only light energy as oxygen evolves at photobioanode upon irradiation and biocathode converts it back to water. Therefore, in this work dual-feature photobioanode based on nanoimprinted gold substrates modified with thylakoids in combination with a capacitive part made of a planar gold substrate coated with a conductive polymer was designed and evaluated, providing open-circuit potential of -0.21 V vs. Ag vertical bar AgCl vertical bar KClsat and a capacitance of ca. 60 F m(-2) both at ambient light and artificial illumination of 400 W m(-2). Combination of thylakoid based dual-feature photobioanode with bilirubin oxidase modified transparent and capacitive indium tin oxide biocathode resulted in a photoelectric biosupercapacitor with remarkable characteristics at ambient light, viz. an open-circuit voltage as high as 0.74 V, which was stable upon charge-discharge cycles during ca. 2 h.

The oxygen reduction reaction (ORR) is important due to high electrochemical potential. Multicopper oxidases (e.g., bilirubin oxidase (BOx)) belong to a class of enzymes that catalyze ORR with low overpotential, and have attracted significant attention in designing bioelectronic devices, viz., biosensors and enzymatic cathodes of biofuel cells. In this work, we present a new concept - an enzyme driven pH electrode system composed of two electrodes: a pH-sensitive BOx-based working electrode and pH-insensitive, a BOx-based reference electrode. ORR-driven pH monitoring was conducted by measuring the potential difference between the two electrodes. Moreover, the electrode system was self-supported and self-calibrating, and no additional electrodes (Pt counter or Ag/AgCl reference) were needed for measurements. The BOx-based pH sensor was tested in continuous and real-time pH monitoring with high accuracy. Also, we present an in-depth mechanistic study explaining the electrode potential-pH dependence, which brings new insights into the operational principle of bilirubin oxidase at different pH.

As the global energy demand continues to increase, the interest in photosynthetic energy conversion is growing accordingly. Chloroplasts, photosynthetic organelles present in plants and algae, are attractive candidates for construction of bio solar cells; however, they have been less studied because of their complex membrane system, which restricts electrochemical communication with an electrode surface. Nevertheless, in this work photobioanodes based on planar and nanoimprinted gold substrates modified with chloroplasts were designed and evaluated. Apparently, nanoimprint lithography contributed to higher photocurrent densities, not only owing to the enlarged real surface area, but also due to boosting electrochemical communication between the photosynthetic organelles and the electrode. Combining chloroplast-modified nanoimprinted gold electrodes with a capacitive part made of a planar gold substrate, coated with a conductive polymer, resulted in a dual-feature photobioanode providing a lower open-circuit potential, i. e., -0.11 V vs. Ag|AgCl|KClsat, and an enhanced capacitance of ca. 37 F m(-2) upon illumination of 400 W m(-2).

High-performance autotolerant bioelectrodes should be ideally suited to design implantable bioelectronic devices. Because of its high redox potential and ability to reduce oxygen directly to water, human ceruloplasmin, HCp, the only blue multicopper oxidase present in human plasma, appears to be the ultimate biocatalyst for oxygen biosensors and also biocathodes in biological power sources. In comparison to fungal and plant blue multicopper oxidases, e.g. Myrothecium verrucaria bilirubin oxidase and Rhus vernicifera laccase, respectively, the inflammatory response to HCp in human blood is significantly reduced. Partial purification of HCp allowed to preserve the native conformation of the enzyme and its biocatalytic activity. Therefore, electrochemical studies were carried out with the partially purified enzyme immobilised on nanostructured graphite electrodes at physiological pH and temperature. Amperometric investigations revealed low reductive current densities, i.e. about 1.65 µA cm−2 in oxygenated electrolyte and in the absence of any mediator, demonstrating nevertheless direct electron transfer based O2 bioelectroreduction by HCp for the first time. The reductive current density obtained in the mediated system was about 12 µA cm−2. Even though the inflammatory response of HCp is diminished in human blood, inadequate bioelectrocatalytic performance hinders its use as a cathodic bioelement in a biofuel cell.

When compared to the general population, socioeconomically disadvantaged communitiesfrequently experience compromised health. Monitoring the divide is challenging since standardizedbiomedical tests are linguistically and culturally inappropriate. The aim of this study was to developand test a unique mobile biomedical testbed based on non-invasive analysis, as well as to explorethe relationships between the objective health measures and subjective health outcomes, asevaluated with the World Health Organization Quality of Life survey. The testbed was evaluated in asocioeconomically disadvantaged neighborhood in Malmö, which has been listed as one of the twelvemost vulnerable districts in Sweden. The study revealed that compared to conventional protocolsthe less intrusive biomedical approach was highly appreciated by the participants. Surprisingly, thecollected biomedical data illustrated that the apparent health of the participants from the ethnicallydiverse low-income neighborhood was comparable to the general Swedish population. Statisticallysignificant correlations between perceived health and biomedical data were disclosed, even thoughthe dependences found were complex, and recognition of the manifest complexity needs to beincluded in further research. Our results validate the potential of non-invasive technologies incombination with advanced statistical analysis, especially when combined with linguistically andculturally appropriate healthcare methodologies, allowing participants to appreciate the significanceof the different parameters to evaluate and monitor aspects of health.