Glucose Molecules Research Articles

Ultrasensitive tapered optical fiber refractive index glucose sensor

Refractive index (RI) sensors are of great interest for label-free optical biosensing. A tapered optical fiber (TOF) RI sensor with micron-sized waist diameters can dramatically enhance sensor sensitivity by reducing the mode volume over a long distance. Here, a simple and fast method is used to fabricate highly sensitive refractive index sensors based on localized surface plasmon resonance (LSPR). Two TOFs (l = 5 mm) with waist diameters of 5 µm and 12 µm demonstrated sensitivity enhancement at λ = 1559 nm for glucose sensing (5–45 wt%) at room temperature. The optical power transmission decreased with increasing glucose concentration due to the interaction of the propagating light in the evanescent field with glucose molecules. The coating of the TOF with gold nanoparticles (AuNPs) as an active layer for glucose sensing generated LSPR through the interaction of the evanescent wave with AuNPs deposited at the tapered waist. The results indicated that the TOF (Ø = 5 µm) exhibited improved sensing performance with a sensitivity of 1265%/RIU compared to the TOF (Ø = 12 µm) at 560%/RIU towards glucose. The AuNPs were characterized using scanning electron microscopy and ultraviolent-visible spectroscopy. The AuNPs-decorated TOF (Ø = 12 µm) demonstrated a high sensitivity of 2032%/RIU toward glucose. The AuNPs-decorated TOF sensor showed a sensitivity enhancement of nearly 4 times over TOF (Ø = 12 µm) with RI ranging from 1.328 to 1.393. The fabricated TOF enabled ultrasensitive glucose detection with good stability and fast response that may lead to next-generation ultrasensitive biosensors for real-world applications, such as disease diagnosis.

Dietary Trehalose as a Bioactive Nutrient

Trehalose is a naturally occurring, non-reducing disaccharide comprising two covalently-linked glucose molecules. It possesses unique physiochemical properties, which account for multiple biological roles in a variety of prokaryotic and eukaryotic organisms. In the past few decades, intensive research on trehalose has uncovered its functions, and extended its uses as a sweetener and stabilizer in the food, medical, pharmaceutical, and cosmetic industries. Further, increased dietary trehalose consumption has sparked research on how trehalose affects the gut microbiome. In addition to its role as a dietary sugar, trehalose has gained attention for its ability to modulate glucose homeostasis, and potentially as a therapeutic agent for diabetes. This review discusses the bioactive effects of dietary trehalose, highlighting its promise in future industrial and scientific contributions.

Electrically Inspired Flexible Electrochemical Film Power Supply for Long-Term Epidermal Sensors.

This paper, for the first time, reports an electrically inspired flexible electrochemical film power supply for long-term epidermal sensors. This device can periodically provide electrical power for several hours after a short-time electrical activation. The electrical activation makes acetylcholine, which is infused into the subcutaneous tissue by iontophoresis. The interstitial fluid (ISF) with glucose molecules is then permeated autonomously for several hours. At this period, the device can provide electrical power. The electrical power is generated from the catalyzing reaction between the glucose oxidase immobilized on the anode and the permeated glucose molecules. After the ISF permeation stops, we give a short-time electrical activation to provide electrical power for several hours again. The power supply is flexible, which makes it adaptively conform to skin. The episodic short-time electrical activation can be enabled by an integrated small film lithium-ion battery. This method extends the service life of a lithium-ion battery 10-fold and suggests the application of small lithium-ion batteries for long-term epidermal sensors.

Monitoring and sensing of glucose molecule by micropillar coated electrochemical biosensor via CuO/[Fe(CN)6]3− and its applications

In recent years, biosensing for the different types of substances affecting our day-to-day life has been evolving to a great extent. The sensing of the glucose level in food as well as the detection of blood sugar levels, are two essential steps for a healthy life. The glucose molecules, on oxidation in the presence of Ferricyanide, generate a current when connected to electrodes. In this paper, the method of current generation due to the oxidation of glucose molecules has been used and a sensor based on the principle of electrochemical sensing has been designed using COMSOL Multiphysics. Furthermore, the variation of current in the range 0-3μA with the concentration of the adsorbed glucose molecules in the range 0-100mgdl-1 on the sensing surface as well as time has been analyzed to achieve a sensitivity of 37.88μAmg-1dl for the sensor. The calculated value of sensitivity for the designed sensor is 37.88μAmg-1dl. The high sensitivity of the sensor is the key factor for its wide range of applications in the field of biosensing.

Sugary solutions

Sugary solutions

Fluorescence Excitation Spectroscopy of Glucose Molecules

The measurement technique and the results obtained by optical spectroscopy during excitation of glucose molecules by photons are described. For the first time, the photoluminescence spectra of glucose were studied in the wavelength range 400-700 nm upon excitation by photons of different energies 3.26-4.51 eV. Peculiarities were found in the luminescence spectra (radiation intensity, positions of maxima), indicating the excitation of the OH hydroxyl radical and the COH carbonyl group as fragments of the glucose molecule by photon impact. X-ray diffraction spectra were measured, which confirmed the presence of glucose hydrate in the studied samples and certain structural changes after interaction with photons. It has been shown that photon irradiation results in modification of glucose molecular crystals both at the macro and micro levels.

Theoretical and experimental study of the diastereoisomers (2S) and (2R)-naringenin-6-C-β-D-glucopyranoside obtained from Clitoria guianensis

In this work the diastereoisomers (2S) and (2R)-naringenin-6-C-β-D-glucopyroside, isolated for the first time from Clitoria guianensis, were studied using the density functional theory. The frontier molecular orbitals and structural properties showed that the diastereoisomers exhibit the same energy gap 166.61kcalmol-1 and structural properties different, where in the S diastereoisomer, the bond length between the chiral carbon and the phenolic group is greater (difference of 0.0126Å). The HPLC data showed that the retention time of the S-diastereoisomer (16.7min) is shorter than that of R, suggesting that the S compound is more polar than R. The HPLC results corroborates with the molecular electrostatic potential which showed that in the S configuration, the electronegative density was more intense overall, particularly in the glucose molecule. The reactivity indices showed that the diastereoisomers are good electrophiles and reactive species. Finally, the absolute configuration of the diastereoisomers were determined using electronic circular dichroism (ECD) spectroscopy and the theoretical spectra were similar to the experimental. METHODS : All calculations of Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) were performed using the program Gaussian 09 and the structures of the diastereoisomers were generated and analyzed using the GaussView program. The optimization and vibrational frequency calculations were performed using the functional CAM-B3LYP and 6-311 + + G(2d,2p) basis set. Conformational searches were performed for R configuration, by molecular mechanics using the MM + , MMFF, and OPLS05 force fields; the entire molecular mechanics simulation was performed using the Maestro/MacroModel software. The calculations for the simulations of the ECD spectra were performed for the eight lowest energy conformers obtained in the geometric optimization step, and the TDDFT at the CAM-B3LYP/6-311 + + G(2d,2p) theory level used. The effects of methanol and chloroform were calculated using the SMD implicit solvent model.

A Glimpse into Milestones of Insulin Resistance and an Updated Review of Its Management

Insulin is the main metabolic regulator of fuel molecules in the diet, such as carbohydrates, lipids, and proteins. It does so by facilitating glucose influx from the circulation into the liver, adipose tissue, and skeletal myocytes. The outcome of which is subjected to glycogenesis in skeletal muscle and lipogenesis in adipose tissue, as well as in the liver. Therefore, insulin has an anabolic action while, on the contrary, hypoinsulinemia promotes the reverse process. Protein breakdown in myocytes is also encountered during the late stages of diabetes mellitus. The balance of the blood glucose level in physiological conditions is maintained by virtue of the interactive functions of insulin and glucagon. In insulin resistance (IR), the balance is disturbed because glucose transporters (GLUTs) of cell membranes fail to respond to this peptide hormone, meaning that glucose molecules cannot be internalized into the cells, the consequence of which is hyperglycemia. To develop the full state of diabetes mellitus, IR should be associated with the impairment of insulin release from beta-cells of the pancreas. Periodic screening of individuals of high risk, such as those with obesity, hypercholesterolemia, and pregnant nulliparous women in antenatal control, is vital, as these are important checkpoints to detect cases of insulin resistance. This is pivotal as IR can be reversed, provided it is detected in its early stages, through healthy dietary habits, regular exercise, and the use of hypoglycemic agents. In this review, we discuss the pathophysiology, etiology, diagnosis, preventive methods, and management of IR in brief.

Eco-friendly fabrication of nonenzymatic electrochemical sensor based on cobalt/polymelamine/nitrogen-doped graphitic-porous carbon nanohybrid material for glucose monitoring in human blood

The design and development of eco-friendly fabrication of cost-effective electrochemical nonenzymatic biosensors with enhanced sensitivity and selectivity are one of the emerging area in nanomaterial and analytical chemistry. In this aspect, we developed a facile fabrication of tertiary nanocomposite material based on cobalt and polymelamine/nitrogen-doped graphitic porous carbon nanohybrid composite (Co-PM-NDGPC/SPE) for the application as a nonenzymatic electrochemical sensor to quantify glucose in human blood samples. Co-PM-NDGPC/SPE nanocomposite electrode fabrication was achieved using a single-step electrodeposition method under cyclic voltammetry (CV) technique under 1 M NH4Cl solution at 20 constitutive CV cycles (sweep rate 20 mV/s). Notably, the fabricated nonenzymatic electroactive nanocomposite material exhibited excellent electrocatalytic sensing towards the quantification of glucose in 0.1 M NaOH over a wide concentration range from 0.03 to 1.071 mM with a sensitive limit of detection 7.8 μM. Moreover, the Co-PM-NDGPC nanocomposite electrode with low charge transfer resistance (Rct∼81 Ω) and high ionic diffusion indicates excellent stability, reproducibility, and high sensitivity. The fabricated nanocomposite materials exhibit a commendable sensing response toward glucose molecules present in the blood serum samples recommends its usage in real-time applications.

Self-assembled, hemin-functionalized peptide nanotubes: an innovative strategy for detecting glutathione and glucose molecules with peroxidase-like activity

Accurately detecting dynamic changes in bioactive small molecules in real-time is very challenging. In this study, a hemin-based peptide assembly was rationally designed for the colorimetric detection of active small molecules. Hemin-functionalized peptide nanotubes were obtained through the direct incubation of hemin (hemin@PNTs) and peptide nanotubes (PNTs) or were coassembled with the heptapeptide Ac-KLVFFAL-NH2 via electrostatic, π–π stacking, and hydrophobic interactions (hemin-PNTs). This new substance is significant because it exhibits the benefits of both hemin and PNTs as well as some special qualities. First, hemin-PNTs exhibited higher intrinsic peroxidase-like activity, which, in the presence of H2O2, could catalyze the oxidation of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) to yield a typical blue solution after 10 min at 25 ℃. Second, hemin-PNTs showed significantly higher activity than that of hemin, PNTs alone, or hemin@PNTs. Hemin-PNTs with a 20.0% hemin content may cooperate to improve catalytic activity. The catalytic activity was dependent on the reaction temperature, pH, reaction time, and H2O2 concentration. The nature of the TMB-catalyzed reaction may arise from the production of hydroxyl radicals. Fluorescence analysis was used to demonstrate the catalytic mechanism. According to this investigation, a new highly selective and sensitive colorimetric technique for detecting glutathione (GSH), L-cysteine, and glucose was established. The strategy demonstrated excellent sensitivity for GSH in the range of 1 to 30 μM with a 0.51 μM detection limit. Importantly, this glucose detection technique, which employs glucose oxidase and hemin-PNTs, is simple and inexpensive, with a 0.1 μM to 1.0 mM linear range and a 15.2 μM detection limit. Because of their low cost and high catalytic activity, hemin-PNTs are an excellent choice for biocatalysts in a diverse range of potential applications, including applications in clinical diagnostics, environmental chemistry, and biotechnology.

Quantifying Microalgae Growth by the Optical Detection of Glucose in the NIR Waveband.

Microalgae have become a popular area of research over the past few decades due to their enormous benefits to various sectors, such as pharmaceuticals, biofuels, and food and feed. Nevertheless, the benefits of microalgae cannot be fully exploited without the optimization of their upstream production. The growth of microalgae is commonly measured based on the optical density of the sample. However, the presence of debris in the culture and the optical absorption of the intercellular components affect the accuracy of this measurement. As a solution, this paper introduces the direct optical detection of glucose molecules at 940-960 nm to accurately measure the growth of microalgae. In addition, this paper also discusses the effects of the presence of glucose on the absorption of free water molecules in the culture. The potential of the optical detection of glucose as a complement to the commonly used optical density measurement at 680 nm is discussed in this paper. Lastly, a few recommendations for future works are presented to further verify the credibility of glucose detection for the accurate determination of microalgae's growth.

Glucose-derived zirconium-containing mesoporous composite for efficient catalytic transfer hydrogenation of furfural to furfuryl alcohol

Meerwein-Ponndorf-Verley (MPV) reaction has been widely acknowledged to be a mild catalytic transfer hydrogenation method for selective reduction of biomass-derived furfural to furfuryl alcohol. Herein zirconium-containing mesoporous composite catalyst was developed through the combination of sol-gel process and soft templating method, in which naturally abundant glucose and F127 triblock copolymer were used as the ligand and pore-forming agent, respectively. The hydroxyl groups in glucose molecules were demonstrated to be coordinated with zirconium ion during hydrolysis-condensation of zirconium precursor, leading to the even dispersion of zirconia nanoparticles in the composite catalyst. The composite catalyst was proven to be highly efficient for catalyzing MPV reduction of furfural with the maximum furfuryl alcohol yield of 93.4% at 180 °C within 180 min in 2-propanol, which served as both solvent and reductant. The composite also showed a good reusability. After five consecutive reaction cycles, furfuryl alcohol yield was slightly reduced from 93.4% to 77.7%, but it could be recovered to 92.8% after the reused composite was regenerated with dilute alkali solution. Batch experiments and systematic characterizations demonstrated that the excellent catalytic performance of composite catalyst was determined by multiple factors mainly including the stronger Lewis acidity, a considerable amount of basic site and the rich mesoporous structure. This study provides a facile strategy to prepare multifunctional composite catalysts using naturally abundant carbohydrates as the feedstocks for lignocellulosic biorefinery.

Synthesis, Characterization, and Electrochemical Evaluation of Copper Sulfide Nanoparticles and Their Application for Non-Enzymatic Glucose Detection in Blood Samples.

Glutathione-capped copper sulfide (CuxSy) nanoparticles with two different average sizes were successfully achieved by using a simple reduction process that involves only changing the reaction temperature. Temperature-induced changes in the size of CuxSy nanoparticles resulted in particles with different optical, morphological, and electrochemical properties. The dependence of electrochemical sensing properties on the sizes of CuxSy nanoparticles was studied by using voltammetric and amperometric techniques. The spherical CuxSy nanoparticles with the average particle size of 25 ± 0.6 nm were found to be highly conductive as compared to CuxSy nanoparticles with the average particle size of 4.5 ± 0.2 nm. The spherical CuxSy nanoparticles exhibited a low bandgap energy (Eg) of 1.87 eV, resulting in superior electrochemical properties and improved electron transfer during glucose detection. The sensor showed a very good electrocatalytic activity toward glucose molecules in the presence of interference species such as uric acid (UA), ascorbic acid (AA), fructose, sodium chloride, and sucrose. These species are often present in low concentrations in the blood. The sensor demonstrated an excellent dynamic linear range between 0.2 to 16 mM, detection limit of 0.2 mM, and sensitivity of 0.013 mA/mM. The applicability of the developed sensor for real field determination of glucose was demonstrated by use of spiked blood samples, which confirmed that the developed sensor had great potential for real analysis of blood glucose levels.

Influence of the Maillard Reaction on Properties of Air-Assisted Electrospun Gelatin/Zein/Glucose Nanofibers.

To develop biodegradable, sustainable, and environment-friendly functional food-packaging materials, gelatin/zein/glucose nanofibers were fabricated through air-assisted electrospinning and then crosslinked by the Maillard reaction under mild conditions (60 °C and 50% relative humidity) in this study. Compared to traditional electrospinning, air-assisted electrospinning increased the yield of nanofibers by 10 times, and the average diameter from 263 nm to 664 nm, while the airflow facilitated uniform and smooth nanofiber formation. During the Maillard reaction in 0-5 days, the gelatin/zein/glucose showed no morphology change. Fourier transform infrared spectra analysis indicated that gelatin interacted with zein through hydrogen bonding and the occurrence of the Maillard reaction among the protein and glucose molecules. After four days of Maillard reaction, the nanofibers presented higher thermal stability, the most hydrophobic surface (water contact angle: 133.6°), and stiffer network structure (elastic modulus of 38.63 MPa, tensile strength of 0.85 MPa). Overall, Maillard-reaction-crosslinked gelatin/zein/glucose nanofibers showed favorable physical properties, which suggests their potential for application in food-active packaging.

Dual mode detection of a glucose molecule using MoS2/NiO electrode

In this article, we demonstrate detection of a glucose molecule present in an alkaline medium at very low concentration (8–10 µM) using commercially available carbon-based paper electrodes. For the effective detection of a glucose molecule the active area of a paper electrode was modified using hydrothermally synthesized NiO nano layers and the NiO nano layers decorated by MoS2 nanostructures. To grow MoS2 nanostructures on NiO nano layers pulsed laser deposition technique was used. The cyclic voltammetry measurements recorded using paper electrode (where active area is modified using NiO layers decorated with MoS2 nanostructures) showed presence of two distinct redox peaks. Appearance of redox peaks at different potentials indicates the oxidation of a glucose molecule via two different mechanisms. Based on the cyclic voltammetry results observed herewith and comparing it with our previously reported results, for the first time we propose the dual mode electrocatalytic activity that may occur on the surface of electrode materials.

The effects of oral trehalose on glycaemia, inflammation, and quality of life in patients with type 2 diabetes: a pilot randomized controlled trial.

Trehalose is a naturally occurring disaccharide of 2 glucose molecules, which has been suggested as a potential therapeutic agent to reduce blood glucose and ameliorate diabetes-related complications in type 2 diabetes (T2D). This study aimed to determine the efficacy of medium-term trehalose treatment in patients with T2D. A double-blind, randomized, placebo-controlled trial in 40 patients with T2D was undertaken; 20 ingested trehalose 3.3 g/day and 20 placebo (sucrose), for 3 months. Parameters of glycaemic indices, high-sensitivity C-reactive protein (CRP), mood status, and quality of life were measured. CRP was significantly lower with trehalose treatment (-0.62 ±0.3 mg/l, p = 0.02); however, no differences in glycaemic indices of fasting blood glucose (FBG) (-7.1 ±10.7 mg/dl, p = 0.15), glycated hemoglobin (HbA1c) (-0.1 ±0.4%, p = 0.73), insulin (0.73 ±0.8 μU/ml, p = 0.39), or insulin resistance (HOMA-IR) (0.19 ±0.33, p = 0.56) were seen between groups after 12 weeks. Depression and stress scores were lower with trehalose compared to the placebo group (p = 0.02 and p = 0.05, respectively), whilst the quality-of-life score was higher with trehalose compared to placebo (p = 0.03) at the end of study. Between-group differences in these indices did not reach statistical significance (-2.36 ±1.20, -2.21 ±1.39 and 3.00 ±1.76 for depression, stress, and quality-of-life score, respectively) (p > 0.05). The pro-oxidant antioxidant balance (PAB) did not differ between groups (-4.6 ±12.8, p = 0.72). 12 weeks of treatment with 3.3 g/day of oral trehalose significantly improves CRP as a marker of inflammation, with potential favourable effects on quality of life, depression, and stress levels, but overall glycaemic control and pro-oxidant-antioxidant balance were unaltered during this time frame.

Improvement of low-intensity long-time running performance in rats by intake of glucosyl hesperidin.

Recently, the use of ergogenic aids in sports by both athletes and fans has increased. Moreover, the overall demand for new ergogenic aids has increased. Hesperidin is a polyphenol that is useful for improving exercise performance by activating energy generation through β-oxidation and oxidative phosphorylation in skeletal muscles. However, it is difficult to use this compound as an ergogenic aid because of its poor water solubility and low bioavailability. Glucosyl hesperidin is formed when one molecule of glucose is transferred to hesperidin via glycosyl-transferase. It is 10,000× more soluble and has 3.7× higher bioavailability than hesperidin. In this study, we assessed whether continuous (14 days) intake of glucosyl hesperidin improves the aerobic exercise capacity of rats during long-term acute exercise. Although glucosyl hesperidin intake did not improve the performance of high-intensity running (30 m/min), we did observe improvement in low-intensity running (15 m/min) (p < 0.05). We demonstrate that in sedentary rats, glucosyl hesperidin intake increased β-oxidation and oxidative phosphorylation in the skeletal muscle (p < 0.05 and p < 0.01, respectively). Glucosyl hesperidin intake may have created a metabolic state useful for long-term exercise. In conclusion, the continuous intake of glucosyl hesperidin improved the aerobic exercise capacity of rats during long-term acute exercise.

Investigation of Glucose Sensing Based on Graphene Conductance

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.

Effects of gestational diabetes on mothers and infants in Pakistan review article

Gestational diabetes mellitus is the type of diabetes that occur during pregnancy and ended after pregnancy in many cases. The term gestation was used in the late twenty centuries. The release of glucose increases during the normal pregnancy and insulin releases from the pancreas and control the glucose level. During gestational period, the insulin release fell down and glucose molecules are not properly breakdown into their substrates. The prevalence of GDM has been observed in the age group of 27 years. GDM affect both children and mother as it causes retinopathy, neuropathy and CVDs. In children, it causes the broad shoulder of fetus and can affect many organs of baby. The high level of glucose can cause complications during delivery. Insulin therapy and metformin are safe treatment for the gestational diabetes. The mechanism underlying the effect cause in the fetus due to gestational diabetes are still known. The studies can be done to find out these mechanisms.

Glucose sandwich assay based on surface-enhanced Raman spectroscopy.

A facile and sensitive glucose sandwich assay using surface-enhanced Raman scattering (SERS) has been developed. Glucose was captured by 3-aminopheyonyl boronic acid (APBA) modified Ag nanoparticles decorated onto a polyamide surface. Then, Ag nanoparticles modified with 3-amino-6-ethynylpicolinonitrile (AEPO) and APBA were used as SERS tags. APBA forms specific cis-diol compounds with glucose molecules avoiding interference by other saccharides and biomolecules in urine enabling its selective detection. As the actual Raman reporter, AEPO exhibited a distinctive SERS peak in the Raman silent region, thus increasing the sensitivity of the glucose detection to 10-11 M. Additionally, the developed SERS assay was reusable, and its applicability in artificial urine samples demonstrated future clinical utility confirming the potential of this innovative technology as a diagnostic tool for glucose sensing.