The prevailing form of bacterial infection is within the urinary tract, encompassing a wide array of bacteria that harness the urinary metabolome for their growth. Through their metabolic actions, the chemical composition of the growth medium undergoes modifications as the bacteria metabolize urine compounds, leading to the subsequent release of metabolites. These changes can indirectly indicate the existence and proliferation of bacterial organisms. Here, we investigate the use of an electronic tongue, a powerful analytical instrument based on a combination of non-selective chemical sensors with a partial specificity for data gathering combined with principal component analysis, to distinguish between infected and non-infected artificial urine samples. Three prevalent bacteria found in urinary tract infections were investigated, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Furthermore, the electronic tongue analysis was supplemented with 1H NMR spectroscopy and flow cytometry. Bacteria-specific changes in compound consumption allowed for a qualitative differentiation between artificial urine medium and bacterial growth.

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.

Bacterial infections can affect the skin, lungs, blood, and brain, and are among the leading causes of mortality globally. Early infection detection is critical in diagnosis and treatment but is a time- and work-consuming process taking several days, creating a hitherto unmet need to develop simple, rapid, and accurate methods for bacterial detection at the point of care. The most frequent type of bacterial infection is infection of the urinary tract. Here, we present a wireless-enabled, portable, potentiometric sensor for E. coli. E. coli was chosen as a model bacterium since it is the most common cause of urinary tract infections. The sensing principle is based on reduction of Prussian blue by the metabolic activity of the bacteria, detected by monitoring the potential of the sensor, transferring the sensor signal via Bluetooth, and recording the output on a laptop or a mobile phone. In sensing of bacteria in an artificial urine medium, E. coli was detected in similar to 4 h (237 +/- 19 min; n = 4) and in less than 0.5 h (21 +/- 7 min, n = 3) using initial E. coli concentrations of similar to 10(3) and 10(5) cells mL(-1), respectively, which is under or on the limit for classification of a urinary tract infection. Detection of E. coli was also demonstrated in authentic urine samples with bacteria concentration as low as 10(4) cells mL(-1), with a similar response recorded between urine samples collected from different volunteers as well as from morning and afternoon urine samples.

AbstractIn Sweden as well as internationally the teaching and research nexus has been described as the defining charac-teristics of higher education promoting generic skills such as information analysis and critical reflection. Vertically Integrated Projects has been proposed as one educational strategy where research and teaching are linked by in-viting students to take active part in actual research projects. The strategy is well aligned to Scholarship of teaching and learning enabling the transition from a teacher-centred accepted knowledge to a student-centred perspective where students are invited as producers of knowledge. The aim of the current study was to explore students’ experiences of participation in a research-based learning activity with academia and industrial partners, designed as a qualitative explorative study using focus group interviews. Findings describe not only factors students find motivating for learning, but also their experience of being part of professional life with its benefits and challenges.

Sweat is a promising biofluid in allowing for non-invasive sampling. Here, we investigate the use of a voltammetric electronic tongue, combining different metal electrodes, for the purpose of non-invasive sample assessment, specifically focusing on sweat. A wearable electronic tongue is presented by incorporating metal electrodes on a flexible circuit board and used to non-invasively monitor sweat on the body. The data obtained from the measurements were treated by multivariate data processing. Using principal component analysis to analyze the data collected by the wearable electronic tongue enabled differentiation of sweat samples of different chemical composition, and when combined with 1H-NMR sample differentiation could be attributed to changing analyte concentrations.

Non-invasive healthcare technologies are an important part of research and development nowadays due to the low cost and convenience offered to both healthcare receivers and providers. This work overviews the recent advances in the field of non-invasive electrochemical biosensors operating in secreted human physiological fluids, viz. tears, sweat, saliva, and urine. Described electrochemical devices are based on different electrochemical techniques, viz. amperometry, coulometry, cyclic voltammetry, and impedance spectroscopy. Challenges that confront researchers in this exciting area and key requirements for biodevices are discussed. It is concluded that the field of non-invasive sensing of biomarkers in bodily fluid is highly convoluted. Nonetheless, if the drawbacks are appropriately addressed, and the pitfalls are adroitly circumvented, the approach will most certainly disrupt current clinical and self-monitoring practices.

Here we report on an entirely new kind of bioelectronic device - a conventional biosupercapacitor, which is built from copper containing redox proteins. Prior to biodevice fabrication, detailed spectroelectrochemical studies of the protein, viz. Acidithiobacillus ferrooxidcats rusticyanin, in solution and in adsorbed state, were performed, including estimation of the redox potential of the T1 site (0.62 V vs. NHE), protein midpoint potential when adsorbed on a self-assembled monolayer (0.34 V vs. NHE), as well as biocapacitance of rusticyanin modified gold electrodes (115 mu F cm(-2)). The symmetrical biosupercapacitor based on two identical gold electrodes modified with rusticyanin is able to capacitively store electricity and deliver electric power accumulated mostly in the form of biopseudocapacitance, when charged and discharged externally. When charged during Just 5 s, the biosupercapacitor with a total capacitance of about 73 mu F cm(-2) provided a maximum of 4 mu A cm(-2) peak current at 0.40 V. The biodevice, which can be charged and discharged at least 50 times without a significant loss of ability to store electric energy, had a low leakage current below 50 nA cm(-2).