Detection Of Glucose Concentration Research Articles

Advancing Glucose Monitoring: A Near-Infrared Device for Continuous Invasive Assessment

Diabetes is a chronic disease that affects millions of people worldwide, with the number of newly diagnosed cases continuing to rise at an alarming rate. Patients diagnosed with diabetes require routine monitoring of their blood glucose levels, which is commonly done through invasive and minimally invasive techniques. However, these methods are often painful, prone to infection, and costly in the long run. Therefore, it is necessary to develop non-invasive, pain-free, affordable glucose monitoring techniques. Near-infrared spectroscopy has emerged as a promising technique among the non-invasive techniques for glucose monitoring, with several studies reporting its efficacy in detecting glucose concentration. This study designed and developed a near-infrared system based on an 1150nm wavelength for continuous non-invasive glucose monitoring. The system gave the output voltages that vary with increased glucose concentrations. It was ascertained from the Clark error grid analysis that the glucose concentration falls within region A and region B. This implies that the device is suitable for measuring glucose concentration non-invasively. As per Bland Altman's analysis, the majority of the data points were within both limits of agreement except one data point that was outside the upper limit of agreement, indicating 93% degree of accuracy, and the residual plot indicates that the regression model for the system is appropriate for predicting non-invasive glucose measurements.

DEMIGOD: A Low-Cost Microcontroller-Based Closed-Loop System Integrating Nanoengineered Sweat-Based Glucose Monitoring and Controlled Transdermal Nanoemulsion Release of Hypoglycemic Treatment with a Software Application for Noninvasive Personalized Diabetes Care.

This study endeavored to design and develop an innovative closed-loop diagnostic and therapeutic system with the following objectives: (a) the noninvasive detection of glucose concentration in sweat utilizing nanonengineered screen-printed biosensors; (b) the management of measured data through a specialized computer system comprising both hardware and software components, thereby enabling the precise control of therapeutic responses via a patch-based nanomedicine delivery system. This initiative addresses the significant challenges inherent in the management of diabetes mellitus, including the imperative need for glucose-level monitoring to optimize glycemic control. Leveraging chronoamperometric results as a foundational dataset and the in vivo hypoglycemic activity of nanoemulsion formulations, this research underscores the efficacy and accuracy of glucose concentration estimation, decision-making mechanism responses, and transdermal hypoglycemic treatment effects, within the proposed system.

A wearable non-enzymatic sensor for continuous monitoring of glucose in human sweat

To enhance personalized diabetes management, there is a critical need for non-invasive wearable electrochemical sensors made from flexible materials to enable continuous monitoring of sweat glucose levels. The main challenge lies in developing glucose sensors with superior electrochemical characteristics and high adaptability. Herein, we present a wearable sensor for non-enzymatic electrochemical glucose analysis. The sensor was synthesized using hydrothermal and one-pot preparation methods, incorporating gold nanoparticles (AuNPs) functionalized onto aminated multi-walled carbon nanotubes (AMWCNTs) as an efficient catalyst, and crosslinked with carboxylated styrene butadiene rubber (XSBR) and PEDOT:PSS. The sensors were then integrated onto screen-printed electrodes (SPEs) to create flexible glucose sensors (XSBR-PEDOT:PSS-AMWCNTs/AuNPs/SPE). Operating under neutral conditions, the sensor exhibits a linear range of 50 μmol/L to 600 μmol/L, with a limit of detection limit of 3.2 μmol/L (S/N = 3), enabling the detection of minute glucose concentrations. The flexible glucose sensor maintains functionality after 500 repetitions of bending at a 180° angle, without significant degradation in performance. Furthermore, the sensor exhibits exceptional stability, repeatability, and resistance to interference. Importantly, we successfully monitored changes in sweat glucose levels by applying screen-printed electrodes to human skin, with results consistent with normal physiological blood glucose fluctuations. This study details the fabrication of a wearable sensor characterized by ease of manufacture, remarkable flexibility, high sensitivity, and adaptability for non-invasive blood glucose monitoring through non-enzymatic electrochemical analysis. Thus, this streamlined fabrication process presents a novel approach for non-invasive, real-time blood glucose level monitoring.

A novel approach to detect glucose concentration using active cavity Whispering Gallery Mode sensor

AbstractThis paper presents a new approach to particle detection using an active microresonator operating in the transparency regime. Simulations demonstrate that when particles interact with the microresonator surface, they induce optical losses. To compensate for these losses, the optical gain is amplified to restore the transparency regime. Simulation results show a linear relationship between nanoparticle concentration and the pump power required to compensate for optical losses. By the use of microresonator with a very high quality factor, this approach offers an accurate and sensitive method for detecting nanoparticles, without the need for complex equipment.

Urine glucose concentration detection biosensor using one-dimensional photonic crystals with periodical and Fibonacci sequences based on Tamm plasmon resonance

This paper presents the design of biosensors utilizing one-dimensional photonic crystals with periodical and Fibonacci sequences for measuring glucose concentration in urine, aimed at facilitating continuous blood glucose monitoring for diabetic patients. Exploiting Tamm plasmon resonance within a photonic band gap in the medium wave infrared band, the biosensor comprises a configuration with a one-dimensional photonic crystal and an Ag layer deposited on an infrared prism, with a urine sample layer in between. Utilizing the transfer matrix method, the reflection spectra for electromagnetic waves are calculated. The wavelength position of the Tamm plasmon resonant dip is influenced by variations in glucose concentration within the urine sample. This is attributed to the distinct refractive indices exhibited by urine samples with different glucose concentrations. Optimizing biosensor performance under various incident angles involves adjusting the Ag layer and urine sample thicknesses while maintaining excellent linear characteristics. The optimal performance of the biosensor with Fibonacci sequence one-dimensional photonic crystal is significantly superior, with a sensitivity of 113,000 nm RIU−1, a figure of merit of 2.05 × 105 RIU−1, and a detection limit of 4.84 × 10−7 RIU. The combination of high performance and a straightforward structure makes the proposed biosensors for detecting urine glucose concentrations promising in biomedical diagnostics.

Defect-rich cypress-leaf-like Cu2+1O@NiF for high-performance non-invasive glucose detection with low detection limit

Non-invasive detection of body fluid glucose concentration is of great significance in the diagnosis and treatment of diabetes, which poses a new challenge to the reduction of the detection limit of glucose sensors. In this work, a novel non-enzymatic glucose sensor (defect-rich cypress-leaf-like Cu2+1O@NiF) was proposed by rapid electrodeposition of cypress-leaf-like Cu2+1O on the surface of nickel foam (NiF) substrate. Due to the high electrochemical active surface area and abundant defects of cypress-leaf-like Cu2+1O providing more catalytic active sites, the prepared non-enzymatic sensor has an ultra-low detection limit (0.9 nM), high sensitivity (88,419.4 μA∙mM−1∙cm−2 (1 nM-0.5 μM) and 2095.5 μA∙mM−1∙cm−2 (1 μM-4.33 mM)) and wide linear range (1 nM-4.33 mM) with good selectivity, reproducibility and stability. Furthermore, the obtained sensors exhibited high detection stability, accuracy and recovery for glucose detection of human body fluid samples, which means that the defect-rich cypress-leaf-like Cu2+1O@NiF electrode is an ideal candidate for non-invasive glucose sensors.

Harnessing Redox Polymer Dynamics for Enhanced Glucose-Oxygen Coupling in Dual Biosensing and Therapeutic Applications.

The burgeoning field of continuous glucose monitoring (CGM) for diabetes management faces significant challenges, particularly in achieving precise and stable biosensor performance under changing environmental conditions such as varying glucose concentrations and O2 levels. To address this, we present a novel biosensor based on the electroless coupling of glucose oxidation catalyzed by flavin-dependent glucose dehydrogenase (FAD-GDH) and O2 reduction catalyzed by bilirubin oxidase (BOD) via a redox polymer, dimethylferrocene-modified linear poly(ethylenimine), FcMe2-LPEI. Initial cyclic voltammetry tests confirm the colocalization of both enzymatic reactions within the potential range of the polymer, indicating an effective electron shuttle mechanism. As a result, we created a hybrid biosensor that operates at open-circuit potential (OCP). It can detect glucose concentrations of up to 100 mM under various O2 conditions, including ambient air. This resulted from optimizing the enzyme ratio to 120 ± 10 mUBOD·UFAD-GDH-1·atmO2-1. This biosensor is highly sensitive, a crucial feature for CGM applications. This distinguishes it from FAD-GDH traditional biosensors, which require a potential to be applied to measure glucose concentrations up to 30 mM. In addition, this biosensor demonstrates the ability to function as a noninvasive, external device that can adapt to changing glucose levels, paving the way for its use in diabetes care and, potentially, personalized healthcare devices. Furthermore, by leveraging the altered metabolic pathways in tumor cells, this system architecture opened up new avenues for targeted glucose scavenging and O2 reduction in cancer therapy.

Detection and intelligent optimization of blood glucose signals based on MXene-assisted sensors

Two-dimensional materials exhibit unique properties that make them ideal for electronic sensing applications, particularly in the field of biosensors. In this study, a Ti3C2Tx MXene/graphene composite was investigated for its potential use in non-invasive blood glucose detection. The strong electrostatic interaction between MXene and graphene nanosheets effectively reduces the self-stacking of both components, resulting in the formation of a porous interlayer structure with enlarged interlayer spacing. This unique structure creates an efficient nanoscale transport channel, which increases the number of active sites and shortens ion diffusion paths. Consequently, the electrochemical properties of the composite membrane are enhanced, making it a promising candidate for sensing element applications. As the human blood glucose level is primarily determined by the glucose concentration in the blood, the concentration of glucose solution serves as the foundation for noninvasive blood glucose concentration detection. In this work, a prediction model was established using the partial least squares fitting method to correlate the electrochemical fingerprinting data with the glucose aqueous solution concentration, and the reliability of the model was verified. To address the limitations of the partial least squares method, which lacks nonlinear fitting capabilities, an RBF (radial basis function) network model was employed. Finally, a genetic algorithm was utilized to perform global optimization of the training parameters of the RBF network, and the quantitative relationship between the NIR spectral data and glucose concentration was validated. The findings of this study provide a theoretical basis for the development of equipment and the improvement of measurement accuracy in the field of human noninvasive glucose detection.

Multi-functional photonic spin Hall effect sensor controlled by phase transition

Abstract Photonic spin Hall effect (PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index (RI). In this work, we propose a multi-functional PSHE sensor based on VO2, a material that can reveal the phase transition behavior. By applying thermal control, the mutual transformation into different phase states of VO2 can be realized, which contributes to the flexible switching between multiple RI sensing tasks. When VO2 is insulating, the ultrasensitive detection of glucose concentrations in human blood is achieved. When VO2 is in a mixed phase, the structure can be designed to distinguish between the normal cells and cancer cells through no-label and real-time monitoring. When VO2 is metallic, the proposed PSHE sensor can act as an RI indicator for gas analytes. Compared with other multi-functional sensing devices with the complex structures, our design consists of only one analyte and two VO2 layers, which is very simple and elegant. Therefore, the proposed VO2-based PSHE sensor has outstanding advantages such as small size, high sensitivity, no-label, and real-time detection, providing a new approach for investigating tunable multi-functional sensors.

Highly efficient MIM based SPR sensor for glucose detection using blueP/WS2 layers

In this article, a highly efficient surface plasmon resonance sensor for glucose detection in urine biosamples is presented. The proposed structure with the Ag-Si-Ag configuration was investigated and optimized using the transfer matrix method. In addition, blueP/WS2 and ZnO layers were implemented to further improve the sensitivity of the sensor by light-mater interaction enhancement in the sensing layer. The multilayer configuration of the optimized sensor consists of SiO2 prism /ZnO /Ag1/ Si/Ag2 /ZnO /blueP/WS2 layers, respectively and operates at λ = 633 nm. Different glucose concentrations of 0 to 15 mg dl−1 (for non-diabetic person), 0.625 gm dl−1, 1.25 gm/dL, 2.5 gm/dL, 5 gm/dL, and 10 gm dl−1 (for diabetic body), with refractive indices of 1.335, 1.336, 1.337, 1.338, 1.341, and 1.347, respectively have been regarded and the qualification parameters of S = 320 deg/RIU, FWHM = 1.5767 deg, FOM = 215.99 RIU−1, and minimum reflectance of 0.0318 have been evaluated. We believe that the proposed sensor could pave the way to easy and accurate detection of glucose concentration which is vital in control or treatment of diabetes.

A non-invasive blood glucose detection using a slotted microstrip antenna sensor

A novel highly sensitive and compact slotted microstrip antenna sensor consisting of slots with defected ground structure is designed. The substrate used in the design of antenna is FR-4 of concise dimensions 30 × 30 × 1.6 mm3 and the developed antenna resonates at 3 GHz. The human finger consisting of several layers namely bone, blood, fat and skin is modelled in the electromagnetic simulation (Computer Simulation Technology) environment resulting in finger phantom. The finger phantom is situated at different locations on proposed antenna for evaluating the concentrations of glucose from 0 to 1000 (mg/dL) and the corresponding shift in frequencies are estimated. For detection of glucose concentration in human blood, the obtained frequency shifts in the proposed work are used. In this proposed work, at the top side of proposed antenna, the finger phantom is situated, an uttermost shift in frequency of 48 MHz, sensitivity of 48 KHz/(mg/dL) and a least possible shift in frequency of 24 MHz, sensitivity of 24 KHz/(mg/dL) are obtained.

MIM waveguide based nano refractive index sensor for hemoglobin and glucose concentration detection in human body

In this study, a nanoscale refractive index sensor structure is proposed, which is realised using a metal-insulator-metal (MIM) waveguide and a grooved circular ring with double disk cavity (GRDD) structure coupled to each other. The finite element method (FEM) was used to analyze and investigate the effects of the variations of each structural parameter on the transmittance spectra and the comprehensive performance of the sensor. Based on the simulation results, the optimum sensitivity parameter of the sensor structure is 2800 nm R−1IU−1 with a figure of merit (FOM) value of 51.9 RIU−1. The sensor structure is capable of being used in biomedical field with sensitivities of 3.895 nm g−L−1, 4.870 nm/gL−1, and 4.955 nm/gL−1, respectively, for detecting hemoglobin of blood types A, B, and O, and 4.48 nm/gL−1, for detecting glucose concentration.

A self-powered and supercapacitive microneedle continuous glucose monitoring system with a wide range of glucose detection capabilities

Continuous detection of sudden changes in blood glucose is essential for individuals with diabetes who have difficulty in maintaining optimal control of their blood glucose levels. Hypoglycemic shock or a hyperglycemic crisis are likely to occurs in patients with diabetes and poses a significant threat to their lives. Currently, commercial continuous glucose monitoring (CGM) has limits in the glucose concentration detection range, which is 40–500 mg/dL, making it difficult to prevent the risk of hyperglycemic shock. In addition, current CGMs are invasive, cause pain and irritation during usage, and expensive. In this research, we overcome these limitations by introducing a novel mechanism to detect glucose concentration using supercapacitors. The developed CGM, which is self-powered and minimally invasive due to the use of microneedles, can detect a wider range of glucose concentrations than commercial sensors. In addition, efficacy and stability were proven through in vitro and in vivo experiments. Thus, this self-powered, microneedle and supercapacitive-type CGM can potentially prevent both hypoglycemic and complications of hyperglycemia without pain and with less power consumption than current commercial sensors.

Amplified frequency-shifted interferometry fiber loop ringdown glucose sensors using side-polished fiber

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.

A Novel Biosensor for the Detection of Glucose Concentration Using the Dual-Peak Long Period Grating in the Near- to Mid-Infrared.

In this article, we demonstrate an improved efficient fibre sensor with a high sensitivity to measure glucose concentrations in the physiological range of human beings, operating in a broad spectral bandwidth from the near- to mid-infrared. The sensor consists of a dual-peak long period grating (DPLPG) with a period of 150 μm inscribed in an optical fibre with a diameter of 80 μm. The investigation of sensing for refractive index results in a sensitivity of ~-885.7 nm/refractive index unit (RIU) and ~2008.6 nm/RIU in the range of 1.30-1.44. The glucose measurement is achieved by the immobilisation of a layer of enzyme of glucose oxidase (GOD) onto the fibre surface for the selective enhancement of sensitivity for glucose. The sensor can measure glucose concentrations with a maximum sensitivity of -36.25 nm/(mg/mL) in the range of 0.1-3.0 mg/mL. To the best of our knowledge, this is the highest sensitivity ever achieved for a measurement of glucose with a long period grating-based sensor, indicating its potential for many applications including pharmaceutical, biomedical and food industries.

Autophagy induces hair follicle stem cell activation and hair follicle regeneration by regulating glycolysis

BackgroundHair follicle stem cells (HFSCs) typically remain quiescent and are activated only during the transition from telogen to anagen to ensure that the hair follicle enters a new cycle. The metabolic behavior of stem cells in tissues is regulated by macroautophagy/autophagy, and changes in HFSC metabolism directly affect their activation and maintenance. However, the role of autophagy in the regulation of HFSC metabolism and function remains unclear.MethodsBack skin samples were obtained from mice at different hair follicle cycle stages, and immunofluorescence staining was used to monitor autophagy in HFSCs. Mouse and human hair follicles were treated with rapamycin (Rapa, an autophagy activator) or 3-methyladenine (3-MA, an autophagy inhibitor). The effects of autophagy on the hair follicle cycle and HFSC were investigated by imaging, cell proliferation staining, and HFSC-specific marker staining. The influence and mechanism of autophagy on HFSC metabolism were explored using RNA sequencing, real-time polymerase chain reaction, immunohistochemical staining, and detection of lactate and glucose concentrations. Finally, the influence of autophagy-induced glycolysis on HFSC and the hair follicle cycle was verified by stem cell characteristics and in vivo functional experiments.ResultsAutophagy in HFSC was highest during the transition from telogen to anagen. Inhibiting autophagy with 3-MA led to early entry into catagen and prolonged telogen, whereas Rapa promoted autophagy and hair growth. Autophagy activated HFSC by increasing the expression and activity of HFSC lactate dehydrogenase (Ldha), thereby transforming HFSC metabolism into glycolysis. Inhibition of Ldha expression counteracted the effects of autophagy.ConclusionsAutophagy activated HFSC by promoting the transition from HFSC metabolism to glycolysis, ultimately initiating the hair follicle cycle and promoting hair growth.Graphical

An electrografted monolayer of polyaniline as a tuneable platform for a glucose biosensor.

Polyaniline (PANI), a nanostructured conducting polymer, has shown significant potential in optical and bioelectrochemical devices. However, its performance and stability on various substrates are hindered by weak adhesion to the surface. In this study, a strongly adherent polyaniline conducting polymer layer with a thickness of five nanometers was electrografted onto an initiating monolayer on gold and tin-doped indium oxide substrates. These electrografted monolayers consist of vertically oriented fully oxidized-protonated (pernigraniline salt) and deprotonated (pernigraniline base) forms of polyaniline. The monolayer exhibits pH-dependent colour changes and it is suitable for enzyme compatibility. In light of these findings, we have developed and characterized an electrochemical glucose biosensor based on the monolayer of polyaniline on a gold electrode. The biosensor utilizes glucose oxidase as the biorecognition element for the selective detection of glucose concentrations in real blood plasma samples.

A photonic crystal fibre-based sensor for glucose concentration detection

In this study, we present a glucose sensor that utilises photonic crystal fibre. The proposed sensor was analysed and demonstrated numerically. A unique structure was infiltrated into the first ring of holes with glucose, serving as the test analyte. We achieved an exceptionally high average spectral sensitivity. Three different wavelengths, 1.1, 1.3 and 1.55 µm, were selected for this investigation. Notably, while the reported sensitivity was already high when the remaining gaps within the structure were filled with air, it was significantly higher when the holes were infiltrated with water at a wavelength of 1.55 µm, calculated to be 0.11493 ps/(nm·km)/(g/l). We anticipate that this sensor will prove to be a valuable tool for glucose sensing and could contribute to further advancements in non-invasive glucose measurement.

An integrated plant glucose monitoring system based on microneedle-enabled electrochemical sensor

Real-time monitoring of glucose concentration changes in plants and access to plant physiological information timely are of great significance to the development of precision agriculture. Here, we innovatively present an electrochemical sensing device that combines microneedle sensors and 3D printing technology to achieve real-time monitoring of glucose in plants in a minimally invasive manner. The device consists of two components: the inner part features a highly efficient sensing interface based on platinum wire (MPt-Au-Nafion-GOx-Pu), while the outer part consists of polymer microneedles formed by 3D printing. Additionally, the polymer hollow microneedle features a slender tip diameter of only 300 μm, minimizing plant damage during the detection procedure. The device shows good detection performance, with a limit of detection (LOD) of 33.3 μM and a detection sensitivity of 17 nA/μM·cm2. It can detect glucose concentrations in the range of 100 μM to 100 mM, providing a unique solution for timely agronomic management of crops tool. By performing 12 h real-time monitoring and salt stress treat on tomato and aloe vera, the results verified the feasibility of integrated device applied to real-time glucose detection in plants.

Glucose Biosensors - State of the Art and Prospects

Rapid glucose concentration detection in technical and biological systems is an important scientific and technical task of modern chemistry, engineering and technology. The article provides an overview of the last technical solutions in this area. The issues of developing first generation biosensors are considered. However, the main disadvantage of such systems was the significant influence of ascorbic and uric acids on the generated signal, which significantly reduced their selectivity and accuracy. To solve this problem, it is possible to use ion-selective membranes such as Nafion and polycarbonate. The second generation of glucose biosensors uses artificial mediators to facilitate electron transfer between the enzyme and the electrode. These mediators can be immobilized directly by the enzyme or introduced into an enzyme-modified electrode. Suitable mediators include conducting organic salts, ferrocene, quinone compounds, ferricyanide, transition metal complexes, phenothiazine and foxazine compounds. Effective interactions between enzymes and mediators are critical for efficient electron transport. Various approaches have been proposed to tailor mediators, such as the use of Os complexes, noncovalent functionalization of carbon nanotubes, and stabilization of artificial mediators. The third generation of enzyme glucose biosensors uses direct electron transfer to perform electrochemical reduction. Various approaches have been considered, including reassembling apoproteins on cofactor-modified enzymes and electrically coupling enzymes to electrode surfaces using redox polymers or nanomaterials such as gold nanoparticles. Such approaches ensure the formation of an effective enzyme-electrode bond. In addition, the thickness of the enzymatic layer can affect the performance of the biosensor. External factors such as temperature, pH and humidity can have a significant impact on the performance of such electrodes.