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The field of strain sensing involves the ability to measure an electrical response that corresponds to a strain.

Abstract: Energy generation from renewable sources and effective management are two critical challenges for sustainable development. Biofuel Cells (BFCs) provide an elegant solution by com-bining these two tasks. BFCs are defined by the catalyst used in the fuel cell and can directly gener-ate electricity from biological substances. Various nontoxic chemical fuels, such as glucose, lactate, urate, alcohol, amines, starch, and fructose, can be used in BFCs and have specific components to oxide fuels. Widely available fuel sources and moderate operational conditions make them promise in renewable energy generation, remote device power sources, etc. Enzymatic biofuel cells (EBFCs) use enzymes as a catalyst to oxidize the fuel rather than precious metals. The shortcoming of the EBFCs system leads to integrated miniaturization issues, lower power density, poor operational sta-bility, lower voltage output, lower energy density, inadequate durability, instability in the long-term application, and incomplete fuel oxidation. This necessitates the development of non-enzymatic bio-fuel cells (NEBFCs). The review paper extensively studies NEBFCs and its various synthetic strat-egies and catalytic characteristics. This paper reviews the use of nanocomposites as biocatalysts in biofuel cells and the principle of biofuel cells as well as their construction elements. This review briefly presents recent technologies developed to improve the biocatalytic properties, biocompatibil-ity, biodegradability, implantability, and mechanical flexibility of BFCs.

The measurement of blood glucose levels is essential for diagnosing and managing diabetes. Enzymatic and nonenzymatic approaches using electrochemical biosensors are used to measure serum or plasma glucose accurately. Current research aims to develop and improve noninvasive methods of detecting glucose in sweat that are accurate, sensitive, and stable. The carbon nanotube (CNT)-copper oxide (CuO) nanocomposite (NC) improved direct electron transport to the electrode surface in this study. The complex precipitation method was used to make this NC. X-ray diffraction (XRD) and scanning electron microscopy were used to investigate the crystal structure and morphology of the prepared catalyst. Using cyclic voltammetry and amperometry, the electrocatalytic activity of the as-prepared catalyst was evaluated. The electrocatalytic activity in artificial sweat solution was examined at various scan rates and at various glucose concentrations. The detection limit of the CNT-CuO NC catalyst was 3.90 µM, with a sensitivity of 15.3 mA cm−2 µM−1 in a linear range of 5–100 µM. Furthermore, this NC demonstrated a high degree of selectivity for various bio-compounds found in sweat, with no interfering cross-reactions from these species. The CNT-CuO NC, as produced, has good sensitivity, rapid reaction time (2 s), and stability, indicating its potential for glucose sensing. Graphical AbstractOther Information Published in: Journal of Electronic Materials License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s11664-022-09727-z

The metamaterial sensor antenna is numerically designed to detect breast cancer using breast cancer cell lines, especially relying on the electrical characteristics of breast cancer cells, and designed antenna is measured and the results are observed. The metamaterial sensor antenna is a simple and efficient antenna which is designed using the Minkowski fractal curve with a ring-shaped Split Ring Resonator (SRR). The SRR is chosen because of its inductive and capacitive resonating properties. In addition, the Minkowski fractal curve is used as a defective ground structure to improve sensor sensitivity and selectivity. The numerical investigations are based on different iterations of the Minkowski fractal curve. In that iteration, the third iteration of the Minkowski fractal gives better results. The designed antenna is tested with breast cancer cell lines, and it resonates at a frequency of 2.35, 2.42, and 2.52 GHz for different dielectric constants and conductivity. The simulated design antenna is tested with different cancer cell lines like MDA-MB-231, MCF-7, and HS758-T to ensure its performance and selectivity. The measured result of the fabricated antenna shows that the antenna design resonates at the same frequency as the simulated antenna results.

Abstract: Regular blood cholesterol control is an integral part of healthcare for detecting cardiovascular issues immediately. Existing procedures are mostly intrusive and necessitate the collection of blood samples. Furthermore, because of the danger of infection, bruising, and/or haematoma, this measurement method may not be appropriate for continuous or regular examinations. As a result, an alternate option is required, which is known as the noninvasive (NI) approach that does not necessitate the collection of blood samples. Because NI approaches give painless and precise answers, they can be used in place of intrusive procedures. This review article includes a comprehensive investigation on NI methodologies and various NI approaches for detecting cholesterol in the bloodstream. It is important to note that medical system possibilities are changing due to the algorithms for NI techniques, which ultimately project the need for patient monitoring via the internet of medical things (IoMT) and artificial intelligence (AI).

Abstract Simple, portable, and low-cost paper-based sensors are alternative devices that have the potential to replace high-cost sensing technologies. The compatibility of the paper base biosensors for both chemical and biochemical accentuates its feasibility for application in clinical diagnosis, environmental monitoring, and food quality monitoring. High concentration of copper in blood serum and urine is associated with diseases like liver diseases, carcinomas, acute and chronic infections, rheumatoid arthritis, etc. Detection of copper concentration can give an early sign of Alzheimer disease. Apart from that genetic Wilson's disease can be detected by evaluating the concentration of copper in the urine. In view of the above advantages, a novel and the highly sensitive paper-based sensor has been designed for the selective detection of Cu2+ ions. The fast and highly sensitive chemiresistive multi-dye system sensor can detect Cu2+ ions selectively in as low as 2.23 ppm concentration. Least interference has been observed for counter ion in the detection of Cu2+. Copper chloride, nitrate, and acetate were used to validate the detection process. This assay provides a very high selectivity of Cu2+ ion over other metal cations such as Na+, Mg2+, Ca2+, etc. The easy preparation and high stability of dye solutions, easy functionalization of the paper-based sensors, high selectivity over other cations, low interference of counter anion, and significantly low detection limit of 2.23 ppm make it an effective Cu2+ ion sensor for real-time application in near future. Graphical Abstract

Sulfite is a common food additive that prevents oxidation from damaging food nutrients, and it has long been used in the food industry as a bleaching agent. It can harm the human body if taken wrongly or excessively. In this study, three dyes (cresol red, chlorophenol red, and bromocresol green) were explored to analyze the presence of sodium sulfite (SS) in an inexpensive, disposable paper sensor with a lower visible detection limit of 0.05 M. This visual paper sensor detects sodium sulfite with high selectivity and sensitivity at room temperature. An IoT-based sensor was also developed to practically apply the developed method, which is rapid and low-cost and can replace heavy-duty instruments. Both these sensors can substantially impact scenarios such as food quality monitoring and detecting sodium sulfite in medicinal items. Graphical Abstract

Aluminium doped zinc oxide (AZO) nanomaterials (AlxZn1-xO) with x fraction varying as 0.02 and 0.04 were synthesized using the auto-combustion method using glycine as a fuel. The synthesized catalysts were characterized with X-ray diffraction (XRD), UV–Visible Spectroscopy (UV–Vis), Raman spectroscopy, Photoluminescence (PL) spectroscopy, and High Resolution Transmission Electron Microscopy (HR-TEM). XRD results showed that synthesized materials possessed good crystallinity, while UV–VIS was employed to find the band gaps of synthesized materials. Raman was used to determine the vibrational modes in the synthesized nanoparticles, while TEM analysis was performed to study the morphology of the samples. Industrial effluents such as indigo carmine and azo carmine G were used to test the photodegradation ability of synthesised catalysts. Parameters such as the effect of catalyst loading, dye concentration and pH were studied. The reduction in crystallite size, band gap and increased lattice strain for the 4% AZO was the primary reason for the degradation in visible irradiation, degrading 97 and 99% equimolar concentrations of indigo carmine and azo carmine G in 140 min. The Al doped ZnO was found to be effective in faster degradation of dyes as compared to pure ZnO in presence of natural sunlight. This work was supported by an NPRP grant from the Qatar National Research Fund under NPRP12S-0131–190030.

The concentration of carbon dioxide (CO