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In many domains, the creation of nonenzymatic glucose sensors with robust electrocatalytic activity and chemical stability is indispensable. However, the design of nanoarchitecture transition metals and their nanocomposites as sensing interfaces for nonenzymatic recognition groups remains a formidable challenge. This review discusses the engineered nanoarchitecture transition metals used as non-enzymatic glucose sensors, with a particular focus on their applications characterized by low cost, high sensitivity, and long-term durability. Central to our discussion is the imperative of crafting nanostructured transition materials with expansive specific surface areas and well-defined active sites to serve as electrochemical sensing platforms. Our objective is to shed light on the enhanced electrochemical behavior toward glucose without reliance on mediators or templates. Leveraging advancements in nanotechnology, this review seeks to elucidate strategies for refining conventional nanostructures to optimize enzyme-free glucose sensing applications. Additionally, we delve into the inherent challenges and potential applications of these sensors for detecting glucose and outline ways to develop better non-enzymatic electrochemical glucose sensors.

Background: In recent years, an increasing number of contact dermatitis cases triggered by acrylates contained in diabetes medical devices have been reported. Acrylates seem to play a major role in the development of irritant contact dermatitis and allergic contact dermatitis (ACD) in diabetic patients. Objectives: To study a group of patients with contact dermatitis caused by diabetes medical devices with a focus on acrylates as possible allergens responsible for contact dermatitis. Patients and Methods: Fifteen patients with diabetes mellitus type 1 and contact dermatitis from diabetic devices were patch tested to 25 acrylate allergens. Results: Three patients (20%) reacted to the following allergens: three patients reacted to isobornyl acrylate (IBOA) and one of them additionally to 2‐hydroxyethyl acrylate (2‐HEA); results were of clinical relevance. All three patients were using insulin pumps and glucose sensors (GS)—in one patient contact dermatitis was towards the insulin pump and the GS, in one patient only towards the insulin pump and in one patient only towards the GS. Twelve patients (80%) did not show any skin reaction towards the allergens tested. Conclusion: A majority of diabetic patients showed no reactions towards any acrylate allergen tested; yet, the presence of untested allergens must be kept in mind. IBOA proved to be a cause of ACD in diabetes patients. 2‐HEA might be another culprit allergen, but its presence in the devices must first be confirmed. [ABSTRACT FROM AUTHOR]

Innovations in digital health and machine learning are changing the path of clinical health and care. People from different geographical locations and cultural backgrounds can benefit from the mobility of wearable devices and smartphones to monitor their health ubiquitously. This paper focuses on reviewing the digital health and machine learning technologies used in gestational diabetes – a subtype of diabetes that occurs during pregnancy. This paper reviews sensor technologies used in blood glucose monitoring devices, digital health innovations and machine learning models for gestational diabetes monitoring and management, in clinical and commercial settings, and discusses future directions. Despite one in six mothers having gestational diabetes, digital health applications were underdeveloped, especially the techniques that can be deployed in clinical practice. There is an urgent need to (1) develop clinically interpretable machine learning methods for patients with gestational diabetes, assisting health professionals with treatment, monitoring, and risk stratification before, during and after their pregnancies; (2) adapt and develop clinically-proven devices for patient self-management of health and well-being at home settings (“virtual ward” and virtual consultation), thereby improving clinical outcomes by facilitating timely intervention; and (3) ensure innovations are affordable and sustainable for all women with different socioeconomic backgrounds and clinical resources. [ABSTRACT FROM AUTHOR]

The current study aims for a simple, rapid, and smartphone‐based enhanced chemiluminescence (eCL) technique for sensitively detecting glucose in human urine. Herein, 1,3‐propanedithiol cross‐linked gold nanoparticles (GNPs‐PDT) via a simple reduction method is synthesized. Further, it is characterized by UV–vis spectroscopy and transmission electron microscopy. The synthesized GNPs‐PDT is found to possess oxidase mimetic activity and generate superoxide radicals from dissolved oxygen, which causes the oxidation of luminol to give a strong and stable CL signal. On the introduction of glucose into the reaction system, a CL quenching phenomenon is observed owing to the tendency of superoxide radicals to oxidize glucose into gluconic acid. Employing the quenching effect of glucose on the eCL signals, a sensor is designed for glucose detection in human urine samples. Under optimized conditions, the proposed method works in a dynamic range from 0.25 to 2 mM (R2 = 0.98) with a detection limit of 0.36 mM. In addition, a simple and portable smartphone‐based imaging technique analyzed by Image J software for eCL‐based glucose sensing is proposed. The developed proof of concept provides good correlations of glucose detection in diabetic patients. [ABSTRACT FROM AUTHOR]

Abstract The utilization of nanomaterials in the biosensor field has garnered substantial attention in recent years. Initially, the emphasis was on enhancing the sensor current rather than material interactions. However, carbon nanotubes (CNTs) have gained prominence in glucose sensors due to their high aspect ratio, remarkable chemical stability, and notable optical and electronic attributes. The diverse nanostructures and metal surface designs of CNTs, coupled with their exceptional physical and chemical properties, have led to diverse applications in electrochemical glucose sensor research. Substantial progress has been achieved, particularly in constructing flexible interfaces based on CNTs. This review focuses on CNT-based sensor design, manufacturing advancements, material synergy effects, and minimally invasive/noninvasive glucose monitoring devices. The review also discusses the trend toward simultaneous detection of multiple markers in glucose sensors and the pivotal role played by CNTs in this trend. Furthermore, the latest applications of CNTs in electrochemical glucose sensors are explored, accompanied by an overview of the current status, challenges, and future prospects of CNT-based sensors and their potential applications.

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Dynamic glucose monitoring is important to reduce the risk of metabolic diseases such as diabetes. Wearable biosensors based on organic electrochemical transistors (OECTs) have been developed due to their excellent signal amplification capabilities and biocompatibility. However, traditional wearable biosensors are fabricated on flat substrates with limited gas permeability, resulting in the inefficient evaporation of sweat, reduced wear comfort, and increased risk of inflammation. Here, we proposed breathable OECT-based glucose sensors by designing a porous structure to realize optimal breathable and stretchable properties. The gas permeability of the device and the relationship between electrical properties under different tensile strains were carefully investigated. The OECTs exhibit exceptional electrical properties (gm ~1.51 mS and Ion ~0.37 mA) and can retain up to about 44% of their initial performance even at 30% stretching. Furthermore, obvious responses to glucose have been demonstrated in a wide range of concentrations (10−7–10−4 M) even under 30% strain, where the normalized response to 10−4 M is 26% and 21% for the pristine sensor and under 30% strain, respectively. This work offers a new strategy for developing advanced breathable and wearable bioelectronics. [ABSTRACT FROM AUTHOR]

Skin adverse reactions to diabetes medical devices have been reported frequently over recent years. Adhesives attaching glucose sensors and continuous insulin infusion sets to the skin are proven to cause both allergic contact dermatitis and irritant contact dermatitis in patients with diabetes mellitus. Several allergens contained in adhesives and/or parts of medical devices are documented to cause allergic contact dermatitis, with acrylate chemicals being the most common culprit-especially isobornyl acrylate (IBOA), but also 2,2′-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate or cyanoacrylates. Epoxy resin, colophonium and nickel were also identified as causative allergens. However, repetitive occlusion, maceration of the skin and resulting disruption of the skin barrier seem to have an impact on the development of skin lesions as well. The purpose of this study is to highlight the burden of contact dermatitis triggered by diabetes medical devices and to show possible mechanisms responsible for the development of contact dermatitis in a group of diabetic patients. [ABSTRACT FROM AUTHOR]

Non-enzymatic sensors with the capability of long-term stability and low cost are promising in glucose monitoring applications. Boronic acid (BA) derivatives offer a reversible and covalent binding mechanism for glucose recognition, which enables continuous glucose monitoring and responsive insulin release. To improve selectivity to glucose, a diboronic acid (DBA) structure design has been explored and has become a hot research topic for real-time glucose sensing in recent decades. This paper reviews the glucose recognition mechanism of boronic acids and discusses different glucose sensing strategies based on DBA-derivatives-based sensors reported in the past 10 years. The tunable pKa, electron-withdrawing properties, and modifiable group of phenylboronic acids were explored to develop various sensing strategies, including optical, electrochemical, and other methods. However, compared to the numerous monoboronic acid molecules and methods developed for glucose monitoring, the diversity of DBA molecules and applied sensing strategies remains limited. The challenges and opportunities are also highlighted for the future of glucose sensing strategies, which need to consider practicability, advanced medical equipment fitment, patient compliance, as well as better selectivity and tolerance to interferences. [ABSTRACT FROM AUTHOR]

Improving the efficiency of glucose oxidation reaction (GOR) is extremely important to build high performance nonenzymatic glucose sensors and fuel cells. In this work, we designed a novel binary (α – β) NiS/PANI nanorods electrocatalyst with polyaniline (PANI) as the substrates and binary (α – β) NiS nanoparticles dispersing on the PANI nanorods. The as-prepared NiS/PANI nanorods were characterized by XRD, XPS and SEM. The electrochemical performance of NiS/PANI nanorods was evaluated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy, which showed highly improved catalytic efficiency for GOR. When used as anodic catalysts in nonenzymatic glucose fuel cells, NiS/PANI nanorods displayed much higher power density of 1343.39 μ W ⋅ cm − 2 with an open circuit voltage of 0.84 V. NiS/PANI/NiS nanorods also presented excellent nonenzymatic sensing performance for glucose detection including a wide sensitivity of 682.21 μ A ⋅ mM − 1 ⋅ cm − 2 (10–9000 μ M) and the low detection limit of 3.33 μ M (S/N = 3). The obviously improved electrochemical properties of NiS/PANI/NiS nanorods for GOR may be due to the synergistic effect of binary (α – β) NiS and PANI nanorods. Binary NiS nanoparticles were deposited on PANI nanorods to construct active catalysts for GOR. NiS/PANI NRs displayed excellent electrocatalytic activity for GOR. Applied in DGFC, NiS/PANI NRs demonstrated an open circuit voltage of 0.84 V and power density of 1343.39 μW⋅cm−2. They also displayed preferable glucose sensing performance with the sensitivity of 682.21 μA⋅mM−1⋅cm−2 in range of 10 μM–9000 μM. The improved electrochemical performance of NiS/PANI NRs may be due to the synergistic effect of NiS and PANI NRs. [ABSTRACT FROM AUTHOR]

Self-supported carbon electrodes have been intensively explored in the fields of materials chemistry, energy storage, and conversion due to the unique features of carbon materials. Herein, we report a facile strategy to construct a freestanding carbon membrane (CM) electrode consisting of a microfiltration CM and two-dimensional (2D) ultrathin Co3O4 nanosheets (NSs), which is successfully applied as an efficient and binder-free carbon electrode in the electrochemical applications of enzyme-free glucose detection and supercapacitors. Owing to the inherent structural merits, including the three-dimensional (3D) interconnected porous network in the membrane, structural integrity, high conductivity, and the well-dispersed and in situ growth of 2D Co3O4 NSs, the obtained Co3O4 NSs/CM demonstrated superior electrochemical performances and excellent long-term operation stability. Our present work paves the path to fabricate low-cost and efficient carbon electrodes with a rational structure design for multifunctional materials. [ABSTRACT FROM AUTHOR]

Glucose sensors as a tool for diabetics to monitor blood glucose are of great significance in the diagnosis and treatment of diabetes. With the rapid development of flexible smart wearable devices the development of glucose sensors based on flexible substrate has also gradually become a research hotspot. Silk has good biocompatibility degradability and flexibility its surface is rich in chemical bonds such as carboxyl hydroxyl and amide bonds which can interact with active substances and it is a good conductive substrate material. The flexible glucose sensor developed by using silk and silk fibroin as the substrate and by being compounded with conductive active materials has excellent sensing performance and good long-term stability. This article aims to review the research progress of silk-based glucose sensors developed based on silk fibroin silk fiber and silk fabric analyze their characteristics and mechanism and prospect their development tendency. In order to fully understand the application of silk in the field of glucose sensors this paper starts with the development of glucose sensors and focuses on the research progress of silk-based glucose sensors on basis of two main kinds of silk and silk fibroin. We first introduced the characteristics and properties of silk and discussed the application of silk yarns silk fabrics and carbonized silk fabrics in the field of glucose sensors. Then we summarized the application of fibroin films and spun fibers based on silk fibroin in the field of glucose sensors. By reviewing the preparation methods and sensing performance of various silk-based glucose sensors we analyzed the role of silk in them and summarized the effect of the silk substrate on the glucose sensing performance. It is hoped that this paper can provide a reference for the design and development of high-performance silk-based flexible glucose sensors. Glucose sensors based on silk fabrics have better mechanical properties higher conductivity and sensitivity while those made of silk fibroin have better biocompatibility and degradability. Finally we compared and analyzed the sensitivity response time detection limit advantages and disadvantages of the silk-based glucose sensors. In sum in virtue of its good characteristics silk has the excellent application value in the field of flexible glucose sensors and the developed glucose sensors show good sensing performance which can also keep the original flexibility and biocompatibility of silk and show good conductivity and ultrahigh response to glucose molecules. However the problems such as the poor fixation rate of silk fibroin to glucose oxidase the poor mechanical properties of silk fibroin films and the weak binding between silk fabric and conductive materials still need to be solved urgently. In addition the cost and maintenance of silk-based glucose sensors are also the factors that cannot be ignored. At present the development of silk-based glucose sensors is mainly based on the silk fibroin membrane and the carbonized silk fabric and there are relatively few studies and applications based on the silk fiber and the silk fabric. The functionalized silk produced by the silkworm feeding method and spinning technology can be applied to the research and development of sensors which would possibly become one of the important research directions of silk-based glucose sensors in the future. Overall although the development of silk-based glucose sensors is still in its infancy its application prospects are very broad and it is worth looking forward to future development. [ABSTRACT FROM AUTHOR]

Glucose sensing based on graphene conductance is investigated by the probe station and COMSOL Multiphysics. The current–voltage (I–V) results from the probe station show that there is a negative linear relationship between graphene conductance and glucose concentration. Using this relationship as the standard curve, the concentration of glucose on graphene can be obtained by measuring the conductance of graphene. The electrical behaviors of different glucose molecules on graphene simulated by COMSOL Multiphysics Toolbox indicate a scattering effect of glucose molecules on current and a more rapidly linear potential drop in the glucose region calculated from the equipotential line distribution, which is consistent with the experimental results. These results provide a new research perspective and method for the sensing of glucose and other biological substances. [ABSTRACT FROM AUTHOR]

Diabetes has become one of the leading deaths causes worldwide. Developing low-cost, rapid, and reusable sensors can provide a solution for continuous glucose monitoring to reduce the diabetic complications that could be fatal. Here, Phenylboronic acid (PBA)-based hydrogel sensors with embedded photonic nanostructures were developed for rapid and continuous glucose quantification within the physiological range. The photonic nanostructures were imprinted on the PBA-based hydrogel using simple and rapid process. Three different sensors: free-standing (FS), stand-alone (SA), and optical fiber (OF) were fabricated and tested in the glucose concentration range of 0–50 mM. A sensitivity of 6, 3, and 1.2 µW/mM was documented for FS, SA, and OF sensors, respectively. A rapid response time of 20 s and saturation time of 3 min were recorded along with a limit of detection of 1 mM. The sensing capabilities of these sensors were examined in both transmission and reflection configurations. Practicality of the sensors was tested using smartphone readout. The optical power was measured using a smartphone exploiting its photodiode and the power changes were correlated with glucose concentrations. These developed sensors may have applications in remote, continuous, and real-time glucose monitoring systems.

Abstract Rational design of microsystems and efficient integration of various functional modules that can directly realize the aimed functions are very attractive for portable and onsite practical applications, which is also significant in developing miniaturized and intelligent electronics and equipment. Unlike the conventional electrochemical glucose sensors that always need auxiliary complex systems for power supply, signal processing, and feedbacks, we design an all‐printed glucose sensor integrated with a zinc ion microbattery (ZIMB) as a micropower source for portable and onsite quick glucose detections. The integrated glucose sensor (GS) and ZIMB (iGS‐ZIMB) system possesses a high areal energy density of 247.3 μWh/cm2 and power density of 1193 μW/cm2 and exhibits high sensitivity up to 464.2 μA/mM/cm2, wide linear range of 0.5–6.0 mM, and good reproducibility in glucose detections. Through a simple amplification circuit design, the glucose concentration signals could be displayed within a short response time of 1.6 s without the need of external auxiliary equipment. Such iGS‐ZIMB microsystem has prominent advantages in efficiency and cost and is promising for onsite medical and healthcare applications.

Carbon composite electrodes are frequently used for enzymatic electrodes but suffer from poor electrocatalytic activity and/or are single use. Our group has recently developed thermoplastic electrodes (TPEs) that use a thermopolymer binder. The electrodes can be easily molded without extensive use of organic solvents enabling catalysts and enzymes to be added directly to the electrode material. The TPE material is bulk‐modified with cobalt phthalocyanine and glucose oxidase, resulting in a robust sensor that is stable for over 100 minutes. These sensors can be molded into intricate shapes and sanded for surface renewal, allowing the sensors to be continuously reused. [ABSTRACT FROM AUTHOR]

This work reported a low-cost, highly sensitive nonenzymatic glucose sensor based on electrochemical electrode decorated by CuCo2O4 nanoparticles. The CuCo2O4 nanoparticles were synthesized by a hydrothermal method using oxalic acid and sodium hydroxide as precipitators. The results showed that the oxalate-assisted CuCo2O4 electrode exhibits excellent glucose sensing performance, including superb sensitivity to $4506.7 \mu \text{A} \cdot $ mm $^{-{1}}\,\,\cdot $ cm $^{-{2}}$ with the correlation coefficient of 0.99674, and the detection limit as low as $0.446 \mu \text{M}$ , as well as extensive linear range from $1 \mu \text{M}$ to 10 mM, which is superior to that of the NaOH-assisted CuCo2O4. Additionally, the glucose sensor had a great selectivity and was not interfered by citric acid (CA), ascorbic acid (AA), dopamine (DA), urea, and so on. Moreover, it also showed good repeatability and long-term stability for up to 28 days. In alkaline solution, the synergistic action of bimetallic ions in CuCo2O4 promotes the electrooxidation of glucose. These findings prove that the oxalate-assisted CuCo2O4 is an advantageous electrode material for nonenzyme glucose sensors. [ABSTRACT FROM AUTHOR]

Background: Isocyanates are well‐known occupational allergens, but can also be present in medical devices. Objectives: To highlight that contact sensitization to isocyanates might contribute to allergic contact dermatitis (ACD) from polyurethane (PU)‐containing diabetes devices and wound dressings. Patients and Methods: Nineteen patients with suspected ACD from diabetes devices and/or wound dressings were patch tested to an isocyanate series. Four wound dressings, six diabetes devices and four monomeric isocyanate patch test preparations were analysed with gas chromatography – mass spectrometry. Results: Eight patients reacted to isocyanates and corresponding amines: 3 to isophorone diisocyanate (IPDI), 4 to 4,4′‐diaminodiphenylmethane (MDA), 4 to 2,4‐toluene diisocyanate (TDI) and 1 to polymeric methylene diphenyl diisocyanate (PMDI). Three of four wound dressings contained isocyanates (methylene diphenyl diisocyanate [MDI], TDI and/or IPDI), whereas five of six diabetes devices contained 4,4′‐MDI, and one of them also IPDI. None of the medical devices contained 1,6‐hexamethylene diisocyanate. Contrary to IPDI, and especially MDI, only the concentration of the TDI patch test preparation corresponded approximately (80%) to its label. Conclusion: Patch tests with isocyanates may be worth‐while in patients with suspected ACD from PU‐containing medical devices. Besides MDA, and PMDI, also TDI might potentially be a marker for MDI‐sensitization. [ABSTRACT FROM AUTHOR]

Background: Insulin pumps and glucose monitoring devices improve diabetes mellitus control and enhance patients' quality of life. However, a growing number of adverse cutaneous reactions related to the use of these devices have been reported. Objective: To investigate the culprits of localized contact dermatitis in paediatric patients with diabetes caused by insulin pumps and glucose monitoring devices. Methods: Retrospective analysis of 15 paediatric patients patch tested as part of a clinical investigation for skin reactions associated with insulin pumps and glucose monitoring devices. Results: Seven patients had positive patch test reactions to isobornyl acrylate (IBOA) and five had positive reactions to benzoyl peroxide (BP). Positive patch test reactions to materials from the glucose sensor and/or insulin pump were seen in 10 of the 15 patients. Three had positive reactions to adhesive remover wipe from Smith and Nephew Remove and four had reactions to EMLA plaster. Conclusion: A high share of patients showed positive reactions to IBOA and/or their medical devices (insulin pumps or glucose devices). A third of patients showed positive reactions to BP. The presence of additional unidentified allergens cannot be excluded, highlighting the importance of access to a full description of the chemical composition of the devices. [ABSTRACT FROM AUTHOR]

Abstract With diabetes mellitus increasing, developing non‐enzymatic glucose sensors to replace enzyme‐based sensors has become more urgent, owing to its intrinsic disadvantages of enzymes. Herein, CuO microflowers were successfully synthesized through a green hydrothermal method with no template or surfactant. X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to study the crystalline structure, elemental composition and morphology of the as‐obtained sample. Then, the CuO microflowers acted as non‐enzymatic glucose sensor electrode material. The electrochemical test results indicate that the glucose oxidation controlled by diffusion at 0.5 V had a short response time(5 s), the linear range was wide(∼11 mM), and the detection limit was low(1.3 µm). Moreover, the CuO microflowers exhibit great selectivity to glucose and have high poison resistance to chloride ions. Thus, all these results imply that the as‐fabricated CuO has a great application prospect for non‐enzymatic glucose sensor electrode material.

Dynamic glucose monitoring is important to reduce the risk of metabolic diseases such as diabetes. Wearable biosensors based on organic electrochemical transistors (OECTs) have been developed due to their excellent signal amplification capabilities and biocompatibility. However, traditional wearable biosensors are fabricated on flat substrates with limited gas permeability, resulting in the inefficient evaporation of sweat, reduced wear comfort, and increased risk of inflammation. Here, we proposed breathable OECT-based glucose sensors by designing a porous structure to realize optimal breathable and stretchable properties. The gas permeability of the device and the relationship between electrical properties under different tensile strains were carefully investigated. The OECTs exhibit exceptional electrical properties (gm ~1.51 mS and Ion ~0.37 mA) and can retain up to about 44% of their initial performance even at 30% stretching. Furthermore, obvious responses to glucose have been demonstrated in a wide range of concentrations (10−7–10−4 M) even under 30% strain, where the normalized response to 10−4 M is 26% and 21% for the pristine sensor and under 30% strain, respectively. This work offers a new strategy for developing advanced breathable and wearable bioelectronics.

Diabetes mellitus remains the leading cause of end-stage kidney disease worldwide. Inadequate glucose monitoring has been identified as one of the gaps in care for hemodialysis patients with diabetes, and lack of reliable methods to assess glycemia has contributed to uncertainty regarding the benefit of glycemic control in these individuals. Hemoglobin A1c, the standard metric to evaluate glycemic control, is inaccurate in patients with kidney failure, and does not capture the full range of glucose values for patients with diabetes. Recent advances in continuous glucose monitoring have established this technology as the new gold standard for glucose management in diabetes. Glucose fluctuations are uniquely challenging in patients dependent on intermittent hemodialysis, and lead to clinically significant glycemic variability. This review evaluates continuous glucose monitoring technology, its validity in the setting of kidney failure, and interpretation of glucose monitoring results for the nephrologist. Continuous glucose monitoring targets for patients on dialysis have yet to be established. While continuous glucose monitoring provides a more complete picture of the glycemic profile than hemoglobin A1c and can mitigate high-risk hypoglycemia and hyperglycemia in the context of the hemodialysis procedure itself, whether the technology can improve clinical outcomes merits further investigation.

We present a simple dual band absorber design and investigate it in the terahertz (THz) region. The proposed absorber works in dual operating bands at 5.1 THz and 11.7 THz. By adjusting the graphene chemical potential, the proposed absorber has the controllability of the resonance frequency to have perfect absorption at various frequencies. The graphene surface plasmon resonance results in sharp and narrow resonance absorption peaks. For incident angles up to 8°, the structure possesses near-unity absorption. The proposed sensor absorber's functionality is evaluated using sensing medium with various refractive indices. The proposed sensor is simulated for glucose detection and a maximum sensitivity of 4.72 THz/RIU is observed. It has a maximum figure of merit (FOM) and Quality factor (Q) value of 14 and 32.49, respectively. The proposed optimal absorber can be used to identify malaria virus and cancer cells in blood. Hence, the proposed plasmonic sensor is a serious contender for biomedical uses in the diagnosis of bacterial infections, cancer, malaria, and other diseases. [ABSTRACT FROM AUTHOR]

The development of noninvasive glucose sensors capable of continuous monitoring without restricting user mobility is crucial, particularly for managing diabetes, which demands consistent and long-term observation. Traditional sensors often face challenges with accuracy and stability that curtail their practical applications. To address these issues, we have innovatively applied a three-dimensional porous aerogel composed of Ti 3 C 2 T x MXene and reduced graphene oxide (MX-rGO) in electrochemical sensing. It significantly reduces the electron-transfer distance between the enzyme's redox center and the electrode surface while firmly anchoring the enzyme layer to effectively prevent any leakage. Another pivotal advancement in our study is the integration of the sensor with a real-time adaptive calibration mechanism tailored specifically for analyzing sweat glucose. This sensor not only measures glucose levels but also dynamically monitors and adjusts to pH fluctuations in sweat. Such capabilities ensure the precise delivery of physiological data during physical activities, providing strong support for personalized health management.

The heterotrimeric flavin adenine dinucleotide (FAD) dependent glucose dehydrogenase derived from Burkholderia cepacia (BcGDH) has many exceptional features for its use in glucose sensing-including that this enzyme is capable of direct electron transfer with an electrode in its heterotrimeric configuration. However, this enzyme's high catalytic activity towards not only glucose but also galactose presents an engineering challenge. To increase the substrate specificity of this enzyme, it must be engineered to reduce its activity towards galactose while maintaining its activity towards glucose. To aid in these mutagenesis studies, the crystal structure composed of BcGDH's small subunit and catalytic subunit (BcGDHγα), in complex with D-glucono-1,5-lactone was elucidated and used to construct the three-dimensional model for targeted, site-directed mutagenesis. BcGDHγα was then mutated at three different residues, glycine 322, asparagine 474 and asparagine 475. The single mutations that showed the greatest glucose selectivity were combined to create the resulting mutant, α-G322Q-N474S-N475S. The α-G322Q-N474S-N475S mutant and BcGDHγα wild type were then characterized with dye-mediated dehydrogenase activity assays to determine their kinetic parameters. The α-G322Q-N474S-N475S mutant showed more than a 2-fold increase in V max towards glucose and this mutant showed a lower activity towards galactose in the physiological range (5 mM) of 4.19 U mg -1 , as compared to the wild type, 86.6 U mg -1 . This resulting increase in specificity lead to an 81.7 gal/glc % activity for the wild type while the α-G322Q-N474S-N475S mutant had just 10.9 gal/glc % activity at 5 mM. While the BcGDHγα wild type has high specificity towards galactose, our engineering α-G322Q-N474S-N475S mutant showed concentration dependent response to glucose and was not affected by galactose., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Koji Sode reports financial support was provided by Arkray Inc, Kyoto, Japan. Koji Sode has patent pending to Arkray Inc. Kyoto, Japan. Junko Okuda-Shimazaki has patent pending to Arkray Inc. Katsuhiro Kojima has patent pending to Arkray Inc. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Skin adverse reactions to diabetes medical devices have been reported frequently over recent years. Adhesives attaching glucose sensors and continuous insulin infusion sets to the skin are proven to cause both allergic contact dermatitis and irritant contact dermatitis in patients with diabetes mellitus. Several allergens contained in adhesives and/or parts of medical devices are documented to cause allergic contact dermatitis, with acrylate chemicals being the most common culprit-especially isobornyl acrylate (IBOA), but also 2,2′-methylenebis(6-tert-butyl-4-methylphenol) monoacrylate or cyanoacrylates. Epoxy resin, colophonium and nickel were also identified as causative allergens. However, repetitive occlusion, maceration of the skin and resulting disruption of the skin barrier seem to have an impact on the development of skin lesions as well. The purpose of this study is to highlight the burden of contact dermatitis triggered by diabetes medical devices and to show possible mechanisms responsible for the development of contact dermatitis in a group of diabetic patients.

Non-enzymatic sensors with the capability of long-term stability and low cost are promising in glucose monitoring applications. Boronic acid (BA) derivatives offer a reversible and covalent binding mechanism for glucose recognition, which enables continuous glucose monitoring and responsive insulin release. To improve selectivity to glucose, a diboronic acid (DBA) structure design has been explored and has become a hot research topic for real-time glucose sensing in recent decades. This paper reviews the glucose recognition mechanism of boronic acids and discusses different glucose sensing strategies based on DBA-derivatives-based sensors reported in the past 10 years. The tunable pKa, electron-withdrawing properties, and modifiable group of phenylboronic acids were explored to develop various sensing strategies, including optical, electrochemical, and other methods. However, compared to the numerous monoboronic acid molecules and methods developed for glucose monitoring, the diversity of DBA molecules and applied sensing strategies remains limited. The challenges and opportunities are also highlighted for the future of glucose sensing strategies, which need to consider practicability, advanced medical equipment fitment, patient compliance, as well as better selectivity and tolerance to interferences.

A comprehensive review of the electroactive materials for non-enzymatic glucose sensing and sensing devices has been performed in this work. A general introduction for glucose sensing, a facile electrochemical technique for glucose detection, and explanations of fundamental mechanisms for the electro-oxidation of glucose via the electrochemical technique are conducted. The glucose sensing materials are classified into five major systems: (1) mono-metallic materials, (2) bi-metallic materials, (3) metallic-oxide compounds, (4) metallic-hydroxide materials, and (5) metal-metal derivatives. The performances of various systems within this decade have been compared and explained in terms of sensitivity, linear regime, the limit of detection (LOD), and detection potentials. Some promising materials and practicable methodologies for the further developments of glucose sensors have been proposed. Firstly, the atomic deposition of alloys is expected to enhance the selectivity, which is considered to be lacking in non-enzymatic glucose sensing. Secondly, by using the modification of the hydrophilicity of the metallic-oxides, a promoted current response from the electro-oxidation of glucose is expected. Lastly, by taking the advantage of the redistribution phenomenon of the oxide particles, the usage of the noble metals is foreseen to be reduced.

Quantum dots (QDs) have emerged as a prominent nanomaterial, finding diverse applications in semiconductors, optoelectronics, and biomedical detection. This study focuses on synthesizing perovskite QDs through a wet chemical method and subsequently modifying them with phenylboronic acid (PBA) to develop a non-enzymatic glucose sensing device. Structural changes post PBA modification and the glucose reaction mechanism were elucidated using XRD, TEM, and FTIR analyses. Photoluminescence (PL) spectroscopy was employed to monitor luminescence variations of CsPbBr 3 /Cs 4 PbBr 6 @PBA (QD@PBA) across different glucose concentrations. In addition to detecting common glucose concentrations (1–5 mM), QD@PBA can also detect extremely low glucose concentrations. Beyond conventional applications in food and blood glucose monitoring, it has significant potential for metabolic monitoring of cellular microenvironments and related drug development. In cell toxicity assessments, QD@PBA demonstrated no adverse reactions or alterations in cellular morphology following a three-day culture period. Its exceptional excitation efficiency, robust selectivity, and biocompatibility suggest promising applications as a human serum glucose sensor. Moreover, the QD@PBA's high sensitivity and prolonged stability position it favorably for further exploration in studying cellular microenvironments. [Display omitted] • A modified QDs were synthesized as a non-enzymatic glucose sensing device. • QD@PBA has non-cytotoxic reaction after three days of cell culture. • QD@PBA is potential applications for the cellular microenvironment observation. • QD@PBA is potential applications for human blood glucose sensing. [ABSTRACT FROM AUTHOR]

• An amplified frequency-shifted interferometry fiber loop ringdown (FSI-FLRD) sensor is proposed for the concentration measurement of glucose solutions. • The concentration of glucose solution is sensed by measuring the decay rate of the CW light propagating in the fiber ringdown loop, without costly pulse light sources and high-speed detectors as in traditional time-domain FLRD techniques. • A bidirectional erbium-doped fiber amplifier and a segment of side-polished fiber are respectively inserted into the fiber loop to compensate the loop attenuation and to act as the sensing probe. The obtained sensitivity was 0.0013 (km−1/%) in the 0–8% concentration range of glucose solutions, with a system stability of 0.75% which surpasses those of traditional FLRD sensing systems. The corresponding detection resolution was 2.63%, which is comparable to the resolutions of the mode interference-based sensors. An amplified frequency-shifted interferometry fiber loop ringdown (FSI-FLRD) sensor is proposed for the concentration measurement of glucose solutions. It detects glucose concentrations by measuring the ringdown distance of the continuous light in the fiber ringdown loop (RDL) instead of the ringdown time of the pulsed light in the loop as in traditional FLRD glucose sensors. A bidirectional erbium-doped fiber amplifier (Bi-EDFA) and a segment of side-polished fiber (SPF) are respectively inserted into the RDL to compensate the loop attenuation and to act as the sensing probe. The proposed optical sensor was tested with glucose solutions in the concentration range from 0 to 14 % at room temperature, which exhibits a linear response with a sensitivity of 0.0013 km−1/% (4.12x10−4 dB/%) for the 0–8 % glucose solutions. Additionally, it also achieved a system stability of 0.75 %, with a measuring resolution of around 2.63 %. The experimental results show the proposed sensor has simple structure, low cost, robust stability and good resolution, and it is a suitable alternative for the detection of glucose concentrations in biological detection, component analysis and on-line quality control in food industry. [ABSTRACT FROM AUTHOR]

With diabetes mellitus increasing, developing non‐enzymatic glucose sensors to replace enzyme‐based sensors has become more urgent, owing to its intrinsic disadvantages of enzymes. Herein, CuO microflowers were successfully synthesized through a green hydrothermal method with no template or surfactant. X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to study the crystalline structure, elemental composition and morphology of the as‐obtained sample. Then, the CuO microflowers acted as non‐enzymatic glucose sensor electrode material. The electrochemical test results indicate that the glucose oxidation controlled by diffusion at 0.5 V had a short response time(5 s), the linear range was wide(∼11 mM), and the detection limit was low(1.3 µm). Moreover, the CuO microflowers exhibit great selectivity to glucose and have high poison resistance to chloride ions. Thus, all these results imply that the as‐fabricated CuO has a great application prospect for non‐enzymatic glucose sensor electrode material. [ABSTRACT FROM AUTHOR]

Isobornyl acrylate (IBOA) has recently caused a number of cases of allergic contact dermatitis (ACD) from its use in medical devices. We would like to enhance the awareness of this issue with the reporting of three Australian cases, involving two adults and a child. We also report a successful solution by using hydrocolloid wafer (Stomahesive®) as a barrier. As IBOA is not usually found on baseline patch test series and does not cross‐react with other acrylic monomers, ACD to IBOA may be missed by clinicians. [ABSTRACT FROM AUTHOR]

Non-invasive glucose monitoring sensors are promising techniques in diabetes management. In particular, optical-based near-infrared glucose sensors are label-free, compact, user-friendly, and inexpensive. They require no daily calibration and can provide continuous glucose level monitoring. However, these sensors are still in the development stage since their accuracy is still not widely accepted by medical professionals. Here, we introduce an optimized dual-channel approach for this kind of sensor where four optodes for short and long channels are employed. The long channel signal that contains useful information about the glucose level can be utilized to calculate the glucose contents in the dermis layer of the skin while the short channel is utilized to measure the interference “noise” signal originating from the epidermis layer. So, the latter can then be removed from the long channel signal. This work investigates the optimal source-detector separation (SDS) of both short and long channels for a wide range of wavelengths from 1200 nm to 1900 nm. Based on the sensitivity distributions of both dermis and epidermis layers and the signal-to-noise ratio, it is suggested that a 2 mm SDS distance with a wavelength of 1450 nm is a potential choice for the short channel. Moreover, 6 mm SDS at the wavelength of 1750 nm is the optimal choice for the long channel. This work may pave the way for further optimization of non-invasive near-infrared glucose sensors that will be widely adopted in the healthcare sector.

Diabetes mellitus is a chronic disease requiring a careful management to prevent its collateral complications, such as cardiovascular and Alzheimer's diseases, retinopathy, nephropathy, foot and hearing impairment, and neuropathy. Self-monitoring of blood glucose at point-of-care settings is an established practice for diabetic patients. However, current technologies for glucose monitoring are invasive, costly, and only provide single snapshots for a widely varying parameter. On the other hand, tears are a source of physiological information that mirror the health state of an individual by expressing different concentrations of metabolites, enzymes, vitamins, salts, and proteins. Therefore, the eyes may be exploited as a sensing site with substantial diagnostic potential. Contact lens sensors represent a viable route for targeting minimally-invasive monitoring of disease onset and progression. Particularly, glucose concentration in tears may be used as a surrogate to estimate blood glucose levels. Extensive research efforts recently have been devoted to develop smart contact lenses for continual glucose detection. The latest advances in the field are reviewed herein. Sensing technologies are described, compared, and the associated challenges are critically discussed.

Aims: This real‐world observational clinical programme evaluated short and medium‐term effects of intermittent flash glucose monitoring on HbA1c, glycaemic variability and lifestyle behavioural changes. Methods: Two first‐generation Libre flash glucose monitoring sensors were provided 3–4 months apart with a food, activity diary, user evaluation survey and treatment modification after each sensor wear. T‐tests were used to compare glucose variables within each sensor (week 1 vs. week 2) and between sensors (1st sensor vs. 2nd sensor). EasyGV software was used to calculate glycaemic variability. Results: From 42 type 1 diabetes and 120 type 2 diabetes participants, there was no statistically significant change in mean HbA1c for participants with type 1 diabetes at 3–4 months after the 1st sensor but there was a statistically significant HbA1c reduction for participants with type 2 diabetes [−4 mmol/mol (−0.4%), p = 0.008], despite no statistically significant differences in carbohydrate intake, exercise frequency and duration. Greater reduction was seen in those with baseline HbA1c> 86 mmol/mol (10%) in both type 1 [−12 mmol/mol (−1.1%), p = 0.009] and type 2 diabetes [−11 mmol/mol (−1.0%), p = 0.001). Both type 1 and type 2 diabetes showed improvements in Glucose Management Indicator and percentage time‐above‐range when comparing week 1 versus week 2 of the same sensor. Higher scan frequency resulted in improved glycaemic parameters and certain measures of glycaemic variability. The majority of participants (85%) agreed that flash glucose monitoring is a useful device but only 60% were keen to use it for daily monitoring. Conclusion: Constant feedback from flash glucose monitoring improves glycaemic parameters within the first week of wear. Intermittent use 3–4 months apart resulted in greater improvements for those with higher baseline HbA1c. [ABSTRACT FROM AUTHOR]

Assessment of glucose concentration is important in the diagnosis and treatment of diabetes. Since the introduction of enzymatic glucose biosensors, scientific and technological advances in nanomaterials have led to the development of new generations of glucose sensors. This field has witnessed major developments over the last decade, as the novel nanomaterials are capable of efficiently catalyzing glucose directly (i.e., act as artificial enzymes, therefore defined nanozymes) or to entrap enzymes that are able to oxidize glucose. Among other nanomaterials, metal–organic frameworks (MOFs) have recently provided a tremendous basis to construct glucose sensing devices. MOFs are large porous crystalline compounds with versatile structural and tuneable chemical properties. In addition, they possess catalytic, peroxidase‐like, and electrochemical redox activity. This review comprehensively summarizes the general characteristics of MOFs, their subtypes, and MOF composites, as well as MOF‐derived materials employed to construct electrochemical, optical, transistor, and microfluidic devices for the detection of glucose. They include enzymatic, nonenzymatic, wearable, and flexible sensing devices and methods. The review also outlines the design and synthesis of MOFs and the working principles of the different transduction‐based glucose sensors and highlights the current challenges and future perspectives. [ABSTRACT FROM AUTHOR]

Background: Skin reactions due to technological devices pose a significant concern in the management of type 1 diabetes (T1D). This multicentric, comparative cross-sectional study aimed to assess the psychological impact of device-related skin issues on youths with T1D and their parents., Methods: Participants with skin reactions were matched in a 1:1 ratio with a control group. Diabetes-related emotional distress was evaluated using the Problem Areas in Diabetes-Teen version (PAID-T) for participants aged 11 to 19 years and the Problem Areas in Diabetes-Parent Revised version (PAID-PR) completed by parents. In addition, glucose control was assessed through glycated hemoglobin (HbA 1c ) values and continuous glucose monitoring (CGM) metrics., Results: A total of 102 children and adolescents were consecutively recruited. Adolescents with skin issues had higher PAID-T scores compared to those without (79.6 ± 21.1 vs 62 ± 16.8; P = .004). Parents of youths with skin reactions also reported higher PAID-PR scores than the control group (34.0 ± 11.0 vs 26.9 ± 12.3; P = .015). No differences were observed in HbA 1c levels (6.9 ± 0.8% vs 6.8 ± 0.8%, P = .555) or CGM glucose metrics between the two groups. Remarkably, 25.5% were forced to discontinue insulin pumps and/or glucose sensors (21.5% and 5.9%, respectively)., Conclusions: Our study highlighted the increased emotional burden experienced by youths with T1D and their parents due to device-related skin reactions, emphasizing the need for further research and interventions in this crucial aspect of diabetes management., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: SP received speaking honoraria from Roche and Movi SpA. NM received speaking honoraria from Movi SpA, Theras, and Novonordisk. MB received speaking honoraria from Movi SpA. All other authors declare no conflicts of interest.

We have proposed Twin Elliptical Core Photonic Crystal Fiber (TEC-PCF) sensor for the detection of blood glucose level under the influence of hemoglobin components. The main featuring of the proposed biosensor is to detect the wide range of blood glucose content with enhanced sensitivity, by utilizing small length of the fiber. In order to achieve this, we have constructed asymmetric TEC-PCF where the elliptical core is filled by blood sample. The numerical sensing characteristics are evaluated using Finite Element Method (FEM). By varying hemoglobin concentrations as 120 g/L, 140 g/L and 160 g/L, we realize enhanced blood glucose sensing with detection range from 0 g/L to 100 g/L. The sensing performance of the proposed biosensor is studied through the coupling length and transmission power spectrum by calculation of effective index of the coupling mode. The obtained maximum wavelength sensitivity under the influence of 160 g/L hemoglobin content is 2.4 nm/(g/L) and 2.42 nm/(g/L) with fiber length of 0.245 mm and 0.215 mm for X and Y polarization, respectively. Further, limit of detection (LOD) is calculated under the influence of 160 g/L hemoglobin content is 0.375 mg/L and 0.372 mg/L for X and Y polarization, respectively. The proposed miniaturized sensing device can be integrated with microfluidic systems for the development of next-generation biosensor applications as point of- care and lab-on-a-chip. [ABSTRACT FROM AUTHOR]

In this paper, a microwave fluidic glucose sensor based on a microwave resonator coupled with an interferometric system is proposed for sensitivity enhancement. The proposed glucose sensor consists of two parts: a sensing part and a sensitivity enhancement part. The former is composed of a rectangular complementary split ring resonator (CSRR), and the latter is composed of a variable attenuator, a variable phase shifter, two hybrid couplers, and an RF power detector. Because the variation in the electrical properties, which is utilized in the microwave detection scheme, with glucose concentration over the possible concentration range in the human body is very small, improvement of the sensitivity is critical for practical use. Thus, the effective sensing area of the rectangular CSRR is determined by considering the electric field distribution. In addition, magnitude and phase conditions for the effective sensitivity enhancement are derived from a mathematical analysis of the proposed interferometric system. In the present experiment, aimed at demonstrating the detection performance as a function of the glucose concentration in the range of 0 mg/dL to 400 mg/dL, the sensitivity is significantly improved by 48 times by applying the derived conditions for effective sensitivity enhancement. Furthermore, the accuracy of the proposed glucose sensor for glucose concentrations at a step of 100 mg/dL is verified by the Clarke error grid. Based on the measurement results, the proposed glucose sensor is demonstrated to be applicable to noninvasive and continuous monitoring in practical environments. [ABSTRACT FROM AUTHOR]

We present a simple dual band absorber design and investigate it in the terahertz (THz) region. The proposed absorber works in dual operating bands at 5.1 THz and 11.7 THz. By adjusting the graphene chemical potential, the proposed absorber has the controllability of the resonance frequency to have perfect absorption at various frequencies. The graphene surface plasmon resonance results in sharp and narrow resonance absorption peaks. For incident angles up to 8°, the structure possesses near-unity absorption. The proposed sensor absorber’s functionality is evaluated using sensing medium with various refractive indices. The proposed sensor is simulated for glucose detection and a maximum sensitivity of 4.72 THz/RIU is observed. It has a maximum figure of merit (FOM) and Quality factor (Q) value of 14 and 32.49, respectively. The proposed optimal absorber can be used to identify malaria virus and cancer cells in blood. Hence, the proposed plasmonic sensor is a serious contender for biomedical uses in the diagnosis of bacterial infections, cancer, malaria, and other diseases.

A low-cost, additively manufactured, biocompatible glucose sensor based on the changes in the unloaded quality factor ($Q_{\mathbf {u}}$) with a single split-ring resonator is presented. An exposition of the fundamentals for the use of the $Q_{\mathbf {u}}$ as sensing parameter with microwave planar resonant sensors is shown. The convenience of this sensing parameter is analyzed from the theoretical point of view, and practical design and optimization guidelines are inferred with a special focus on the optimization of $Q_{\mathbf {u}}$ sensitivity to glucose concentration. For practical demonstration and experimental assessment, a novel inverted microstrip configuration is considered, built upon a customized structure made with a certified biocompatible material thanks to 3-D printing techniques, which is aimed to provide for a stronger interaction between the electromagnetic fields and the sample. Two metallization solutions are investigated, yielding devices operating at 4.50 and 4.62 GHz, with operating $Q_{\mathbf {u}}$ of 16.36 and 22.00, relative $Q_{\mathbf {u}}$ sensitivities of 1.377 and 2.727, $Q_{\mathbf {u}}$ sensitivities to glucose content within the physiological range of $0.3\times 10^{-3}$ per mg/dL and $0.6\times 10^{-3}$ per mg/dL, sensing areas of approximately $11.7\times8.8$ mm2 and total structure sizes of 950.0 $\times 35.0\times3.5$ mm3. The devices show good performance with water–glucose solutions covering a wide range of concentrations, involving physiological as well as industry-related ones. [ABSTRACT FROM AUTHOR]

Nowadays, robust sensors for glucose-sensing application are almost a necessity for every diabetic individual. In this work, a (20 mm $\times10$ mm) contact-based sensor has been successfully realized on a thin and flexible polyamide substrate, with the sensing area being a bifilar spiral resonator (BSR). The proposed sensor was based on detecting resonance frequencies shifts at ultrahigh frequencies (UHFs) as a result of changes in the glucose concentration. The BSR acts as a cascaded metasurface which, at around the resonant frequency, forms a plasmon dispersion at the interface between a glucose solution and the BSR. An empirical formula has been developed to express the sensing sensitivity as a function of the loss factor, the oscillator strengths and the steady state permittivity. The model has been experimentally validated with an in vitro measurement on an aqueous glucose solution and an ex-vivo measurement on a serum blood solution. The measured results suggest that there exists a positive and linear correlation between glucose concentration and the resonant frequency shift within the clinical diabetic range. The sensor sensitivity was 250 megahertz (MHz)/(mg/mL) for the aqueous glucose solution and 130 MHz/(mg/mL) for the serum blood along with a $Q$ -factor of 20. Overall, the measured results were highly consistent with our theoretical expectation. Moreover, the proposed sensor was highly resistant to bending losses. [ABSTRACT FROM AUTHOR]

Thanks to rapid technological innovation over the last decade, a wide range of wearable devices have emerged, playing an inspiring role in healthcare, diagnostics, and sports monitoring. This review summarizes recent progress in the development and application of electrochemical (EC) sweat sensors and self-powered systems for wearable applications. Presented here are the most common types of EC sweat sensors, namely potentiometric ion-selective electrodes, amperometric enzymatic and non-enzymatic sensors, as well as differential pulse voltammetric sensors. The sensing principle and novel functional nanomaterials that are used to enhance the performance of wearable sweat sensors and their applications are summarized. The recent advancement of battery-free wearable devices is presented, including self-powered biofuel cells (BFC), energy harvesting from novel materials and its strategy, are also discussed. The challenges in, and opportunities for, the development of sweat sensor-based wearable systems moving forward are reviewed, with the aim of shedding some light on future directions. [ABSTRACT FROM AUTHOR]

Non-invasive glucose monitoring sensors are promising techniques in diabetes management. In particular, optical-based near-infrared glucose sensors are label-free, compact, user-friendly, and inexpensive. They require no daily calibration and can provide continuous glucose level monitoring. However, these sensors are still in the development stage since their accuracy is still not widely accepted by medical professionals. Here, we introduce an optimized dual-channel approach for this kind of sensor where four optodes for short and long channels are employed. The long channel signal that contains useful information about the glucose level can be utilized to calculate the glucose contents in the dermis layer of the skin while the short channel is utilized to measure the interference “noise” signal originating from the epidermis layer. So, the latter can then be removed from the long channel signal. This work investigates the optimal source-detector separation (SDS) of both short and long channels for a wide range of wavelengths from 1200 nm to 1900 nm. Based on the sensitivity distributions of both dermis and epidermis layers and the signal-to-noise ratio, it is suggested that a 2 mm SDS distance with a wavelength of 1450 nm is a potential choice for the short channel. Moreover, 6 mm SDS at the wavelength of 1750 nm is the optimal choice for the long channel. This work may pave the way for further optimization of non-invasive near-infrared glucose sensors that will be widely adopted in the healthcare sector. [ABSTRACT FROM AUTHOR]

In this work, the CoS was synthesized by the solvothermal method. The PANI and PANI-CoS composites (1, 5, and 15 wt % CoS in the PANI matrix) were synthesized by the oxidative polymerization method. The PXRD pattern confirmed CoS and PANI peaks matched with JCPDS cards. CoS was successfully embedded in the PANI matrix. The surface morphology of the CoS microspheres are flower-like and shows crossed nanoflakes with a thickness of around 40 nm. These CoS microspheres are transformed into nanoparticles by the presence of PANI. The Nickel Foam/Polymer Composites/GOx were prepared by drop-coating the PEG water-dispersed PCs-modified nickel foam electrode and immobilized with the enzyme glucose oxidase. The CV studies were carried out for three-electrode systems. The sensitivity of PCs toward different concentrations of glucose ranging from 1 mM to 1000 mM was evaluated. Also the enzymatic reaction evaluated by Michaelis-Menten kinetic exhibits a high affinity of GOx to glucose. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Novel NiO/C@rGO nanocomposites derived from Ni(gallate) was prepared by a simple pyrolysis treatment. • The nanocomposite showed high selectivity and sensitivity toward glucose determination. • The proposed mechanism for non-enzymatic detection of glucose was discussed. The development of suitable substrate materials in electrochemical sensors is essential for rapid and reliable quantification in the diagnostic and clinical fields. In this paper, NiO/C@rGO nanocomposite was synthesized through nickel (gallate) pyrolysis with graphene oxide and employed as a substrate to construct a glucose sensor with high selectivity and sensitivity. The structural characterizations of NiO/C@rGO were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, energy disperse spectroscopy, and elemental mapping. The newly fabricated biosensor (NiO/C@rGO/GCE) exhibited a high sensing performance with an extensive dynamic linear range (from 1 μM to 1115 μM) and a low limit of detection (LOD) 0.658 μM (S/N = 3) toward glucose. In addition, the NiO/C@rGO-based sensor displayed good stability, favorable repeatability, and anti-interference ability for determining glucose. It was also used to measure glucose in serum samples, and satisfactory results were attained. These results illustrated that the NiO/C@rGO nanocomposite could be applied as an excellent electrochemical sensing material with high sensitivity to diagnose glucose-related illnesses. [ABSTRACT FROM AUTHOR]