Selective Detection Of Glucose Research Articles

Integrating Cu/CuxO ternary nanocomposites with multi-walled carbon nanotubes enabling a high-performance nonenzymatic amperometric glucose sensor

We developed a new nonenzymatic amperometric glucose sensor by integrating a ternary nanocomposite, Cu/Cu2O/CuO (Cu/CuxO), with multi-wall carbon nanotubes (Cu/CuxO@MWCNTs) as the electrocatalyst. The Cu/CuxO@MWCNTs nanocomposite is prepared via an electroless plating process followed by thermal treatment. The constructed nanocomposites are systematically characterized with a transmission electron microscope, an X-ray diffractometer, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy, respectively. The Cu/CuxO@MWCNTs nanocomposites-modified glassy carbon electrodes exhibit high electrocatalytic activity toward glucose electrooxidation under alkaline conditions. The efficient electrocatalytic activity of Cu/CuxO@MWCNTs for glucose electrooxidation is utilized for glucose detection using Cu/CuxO@MWCNTs-modified glassy carbon electrodes. The Cu/CuxO@MWCNTs-modified electrode displays an excellent sensing performance within a wide analyte concentration from 0.005-6,000 M (low detection limit is calculated to be 0.003 μM) with superior stability, selectivity, repeatability, and reproductivity. This as-prepared electrochemical sensor is successfully applied to selective glucose detection with satisfactory results.

Selective Detection of Glucose by Linear Sweep Voltammetry Using a Copper–Polyaniline Modified Glassy Carbon Electrode

Selective Detection of Glucose by Linear Sweep Voltammetry Using a Copper–Polyaniline Modified Glassy Carbon Electrode

Fluorescent Enzymatic Sensor Based Glucose Oxidase Modified Bovine Serum Albumin-Gold Nanoclusters for Detection of Glucose.

An enzymatic fluorescent probe is developed for the selective detection of glucose. In this work, a Bovine Serum Albumin stabilized gold nanocluster (BSA-AuNCs) was synthesized by microwave assisted method, and it is modified with glucose oxidase, thereby a fluorescent enzymatic sensor (BSA-AuNCs@GoX) was designed for the sensitive detection of glucose with a limit of detection of 0.03 mM. The red fluorescence exhibited by the probe is quenched by the production of H2O2 on addition of glucose via. a static quenching mechanism from UV visible absorption and Fluorescence lifetime results. The developed probe exhibits good selectivity and sensitivity with other coexisting molecular species such as glycine, creatinine, methionine, histidine, uric acid, albumin, and ions such as sodium, potassium, calcium, magnesium, zinc etc. that appear in the body fluid. The practical applicability was studied in paper strip and extended its reproducibility in biological matrixes such as human serum and urine and found a good recovery percentage of 94-101 %. By this way, we have fabricated an effective fluorescent enzymatic "turn-off" sensing probe for the detection of glucose.

Fluorescent Determination of Glucose in Human Perspiration Using a Sensing Platform Composed of CdTe Quantum Dots (QDs) with a Zeolitic Imidazolate Framework (ZIF-8) (QD@ZIF-8)

In sports, noninvasive analysis and monitoring of the human health condition are important to ensure the well-being of the sportsperson and prevent injuries. Multiple biomarker-related substances in body fluids can serve as physiological information and health or health status indicators to detect possible dangers to the athlete. As the glucose content in perspiration may vary with gender and the parts of the body, it is important to develop a highly sensitive and selective glucose detection method. Here, CdTe quantum dots (QDs) are wrapped with a zeolitic imidazolate framework (ZIF-8) to create a fluorescence sensor platform (QD@ZIF-8), which is successfully employed for the determination of glucose levels in human perspiration. The synthesis of QD@ZIF-8 is quickly and easily achieved at room temperature through a one-step process. The resulting platform exhibits strong fluorescence, emitting at a wavelength of 587 nm when excited at 360 nm. The application of ZIF-8 as a transition layer to envelope the CdTe QDs effectively provide chemical and thermal stability, excellent dispersibility, and size selectivity. The sensor is utilized to measure perspiration glucose levels in a diverse group of male and female subjects, revealing significant differences in perspiration glucose concentrations.

Green Synthesis of PtPdNiFeCu High-Entropy Alloy Nanoparticles for Glucose Detection.

High-entropy alloys have long been used as a new type of alloy material and have attracted widespread concern because of their excellent performance, including their stable microstructure and particular catalytic properties. To design a safer preparation method, we report a novel approach targeting green synthesis, using tea polyphenols to prepare PtPdNiFeCu high-entropy alloy nanoparticles for glucose detection. The fabricated sensors were characterized by transmission electron microscopy and electrochemical experiments. Physical characterization showed that the nanoparticle has better dispersibility, and the average particle size is 7.5 nm. The electrochemical results showed that Tp-PtPdNiFeCu HEA-NPs had a high sensitivity of 1.264 μA mM-1 cm-2, a low detection limit of 4.503 μM, and a wide detection range of 0 - 10 mM. In addition, the sensor has better stability and selectivity for glucose detection.

Utilizing Nanozymatic Activity of Copper-Functionlized Mesoporous C3N5 for Sensing of Biomolecules.

Designing unique nanomaterials for the selective sensing of biomolecules is of significant interest in the field of nanobiotechnology. In this work, we demonstrated the synthesis of ordered and Cu nanoparticles functionalized mesoporous C3N5 with unique peroxidase like nanozymatic activity for the ultrasensitive and selective detection of glucose and glutathione. A nano hard-templating technique together with the in-situ polymerization and self-assembly of Cu and high N-containing CN precursor was adopted to introduce mesoporosity as well as high N and Cu content in mesoporous C3N5. Due to the ordered structure and highly dispersed Cu in the mesoporous C3N5, a large enhancement of the peroxidase mimetic activity in the oxidation of a redox dye in the presence of hydrogen peroxide could be obtained. Additionally, the optimized Cu functionalized mesoporous C3N5 exhibited excellent sensitivity to glutathione with a low detection limit of 2.0 ppm. The strong peroxidase activity of the Cu functionalized mesoporous C3N5 was also effectively used for the sensing of glucose with the detection limit of 0.4 mM through glucose oxidation with glucose oxidase. This unique Cu functionalized mesoporous C3N5 has the potential for detecting various molecules in the environment as well as for next-generation glucose and glutathione diagnostic devices.

Combined experimental and theoretical investigation of the pyrene-based hydrazide-hydrazone phenylboronic acid molecules

Diabetes is a significant public health issue worldwide and can cause serious consequences for daily functioning and health. Several molecular design strategies have been proposed to detect glucose, among these, phenylboronic acid (PBA) is considered to have the potential as a glucose binder. Nevertheless, most of the PBA derivatives are used in alkaline media to achieve glucose sensing. In this work, we first report the glucose sensor based on hydrazide-hydrazone PBA molecules that can function without the need for adding an alkaline agent. A series of novel pyrene-based hydrazide-hydrazone PBA with 1,2-, 1,3- and 1,4-substituted derivatives, namely 3a, 3b and 3c, respectively, were synthesized. The experimental and theoretical studies demonstrated that compound 3a might have intramolecular Lewis acid-base interactions between the boron and nitrogen atoms, leading to high sensitivity to glucose. Alternatively, compound 3c revealed intermolecular Lewis acid-base interactions and resulted in the selective glucose detection. We proved the cooperative effect of Lewis acid-base interaction, π-π stacking and hydrogen bonding may play an important role in the design of the alkaline-free activated glucose sensor.

Iron-Coordinated L-Lysine-Based Nanozymes with High Peroxidase-like Activity for Sensitive Hydrogen Peroxide and Glucose Detection.

It is crucial to develop sensitive and accurate sensing strategies to detect H2O2 and glucose in biological systems. Herein, biocompatible iron-coordinated L-lysine-based hydrogen peroxide (H2O2)-mimetic enzymes (Lys-Fe-NPs) were prepared by precipitation polymerization in aqueous solution. The coordinated Fe2+ ion acted as centers of peroxidase-like enzymes of Lys-Fe-NPs, and the catalytic activity was evaluated via the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2. Therefore, a sensitive colorimetric detection sensor for H2O2 was constructed with a linear range of 1 to 200 μM and a detection limit of 0.51 μM. The same method could also be applied to highly sensitive and selective detection of glucose, with a linear range of 0.5 to 150 μM and a detection limit of 0.32 μM. In addition, an agarose-based hydrogel biosensor colorimetric was successfully implemented for visual assessment and quantitative detection of glucose. The design provided a novel platform for constructing stable and nonprotein enzyme mimics with lysine and showed great potential applications in biorelevant assays.

A Highly Porous and Flexible Carbon Nanotube Array Coated with Gold Nanoparticles: Application in Non‐Enzymatic Ultrasensitive Detection and Monitoring of Blood/Saliva Glucose

AbstractFlexible, reusable, and ultrasensitive glucose sensors are the need of the hour for advanced health monitoring, specifically for economical diabetes management in low‐income countries. Here, we demonstrate an ultra‐sensitive, and extremely lightweight non‐enzymatic glucose sensor based on gold nanoparticles sputtered carbon nanotube aerogel film (Au‐CNT), which is flexible, durable, reusable, and portable. The flexible Au‐CNT aerogel non‐enzymatic glucose sensor showed remarkable sensitivity of 779 μA mM−1 cm−2, a wide linear range of 0.1 mM to 6 mM and a limit of detection (LoD) of 1.47 μM. The sensitivity of our sensor is highest among literature‐reported carbon nanomaterials‐based flexible glucose sensors for selective detection of glucose in blood serum/saliva samples. The Au‐CNT aerogel shows the potential application as practical non‐invasive and invasive self‐monitoring glucose sensor. Therefore, highly sensitive and paper‐thin Au‐CNT electrode is a promising candidate for future commercial robust flexible and wearable biosensor applications.

Enhanced glucose sensing performance of p-n Cu2O homojunction promoted by Cu(I)/Cu(III) redox process

Developing enzyme-free glucose sensors that rely on transitional metal oxides has become a tendency to satisfy the growing demands of glucose monitor. In this work, the photoactive Cu2O film has been prepared by electrochemical deposition for effective and selective detection of glucose. Characterizations including XRD, Raman spectrum, UV–vis reflectance spectrum, and electrochemical testing were performed. We found that the as-prepared Cu2O films were self-composed of p-n Cu2O homojunction structure with enhanced photocurrent response for PEC-type glucose sensing. Further investigation on p-n Cu2O indicates that the intrinsic charge recombination has been retarded, which paves the way to construct photoelectrochemical-type (PEC-type) glucose sensors. Benefitted from the properties of p-n Cu2O homojunction, high sensitive PEC-type glucose detection has been achieved at the dual-range of 1 μM to 10 μM and 20 μM to 11 mM. We attribute to our investigations can provide in-depth understanding on electric assist-redox and glucose catalytic processes for the detection of glucose, that may guide the fabrication of glucose sensors with high sensitivity and selectivity.

Diboronic-Acid-Based Electrochemical Sensor for Enzyme-Free Selective and Sensitive Glucose Detection.

A diboronic acid anthracene-based fluorescent system for detecting blood glucose could be used for 180 days. However, there has not yet been a boronic acid immobilized electrode to selectively detect glucose in a signal-increased way. Considering malfunctions of sensors at high sugar levels, the electrochemical signal should be increased proportionally to the glucose concentration. Therefore, we synthesized a new diboronic acid derivative and fabricated the derivative-immobilized electrodes for the selective detection of glucose. We performed cyclic voltammetry and electrochemical impedance spectroscopy with an Fe(CN)63-/4- redox pair for detecting glucose in the range of 0-500 mg/dL. The analysis revealed increased electron-transfer kinetics such as increased peak current and decreased semicircle radius of Nyquist plots as the glucose concentration increased. The cyclic voltammetry and impedance spectroscopy showed that the linear detection range of glucose was 40 to 500 mg/dL with limits of detection of 31.2 mg/dL and 21.5 mg/dL, respectively. We applied the fabricated electrode to detect glucose in artificial sweat and obtained 90% of the performance of the electrodes in PBS. Cyclic voltammetry measurements of other sugars such as galactose, fructose, and mannitol also showed linear increased peak currents proportional to the concentrations of the tested sugars. However, the slopes of the sugars were lower than that of glucose, indicating selectivity for glucose. These results proved the newly synthesized diboronic acid is a promising synthetic receptor for developing a long-term usable electrochemical sensor system.

Interactions of Catalytic Enzymes with n-Type Polymers for High-Performance Metabolite Sensors.

The tight regulation of the glucose concentration in the body is crucial for balanced physiological function. We developed an electrochemical transistor comprising an n-type conjugated polymer film in contact with a catalytic enzyme for sensitive and selective glucose detection in bodily fluids. Despite the promise of these sensors, the property of the polymer that led to such high performance has remained unknown, with charge transport being the only characteristic under focus. Here, we studied the impact of the polymer chemical structure on film surface properties and enzyme adsorption behavior using a combination of physiochemical characterization methods and correlated our findings with the resulting sensor performance. We developed five n-type polymers bearing the same backbone with side chains differing in polarity and charge. We found that the nature of the side chains modulated the film surface properties, dictating the extent of interactions between the enzyme and the polymer film. Quartz crystal microbalance with dissipation monitoring studies showed that hydrophobic surfaces retained more enzymes in a densely packed arrangement, while hydrophilic surfaces captured fewer enzymes in a flattened conformation. X-ray photoelectron spectroscopy analysis of the surfaces revealed strong interactions of the enzyme with the glycolated side chains of the polymers, which improved for linear side chains compared to those for branched ones. We probed the alterations in the enzyme structure upon adsorption using circular dichroism, which suggested protein denaturation on hydrophobic surfaces. Our study concludes that a negatively charged, smooth, and hydrophilic film surface provides the best environment for enzyme adsorption with desired mass and conformation, maximizing the sensor performance. This knowledge will guide synthetic work aiming to establish close interactions between proteins and electronic materials, which is crucial for developing high-performance enzymatic metabolite biosensors and biocatalytic charge-conversion devices.

A Co(II)–organic framework and peroxidase mimetic Hemin@metal–organic framework and its application in the colorimetric analysis of glucose

A Co(II)‐organic framework (Co‐MOF), [Co3(3,5‐bimpy)2(5‐cpia)2(H2O)2], was constructed via the hydrothermal reaction of 3,5‐bis(1‐imidazoly)pyridine (3,5‐bimpy) and 5‐(2′‐carboxylphenoxy)isophthalic acid (5‐H3cpia). The Co‐MOF possessed a three‐dimensional (3D) porous architecture with the porosity of 22.4% per unit volume. The Co‐MOF@Hemin composite was further constructed via the encapsulation of Hemin into the Co‐MOF material. The constructed Co‐MOF@Hemin exhibited satisfactory peroxidase‐like activity through catalytic oxidation of the colorless peroxidase substrate 3,3,5,5‐tetramethylbenzidine (TMB) to a blue‐colored oxTMB in the presence of H2O2. Hence, the detection of H2O2 was achieved with a wide linear range from 0.005 to 0.5 mM (R2 = 0.992) and a low detection limit of 1.26 μM. More importantly, the peroxidase‐like Co‐MOF@Hemin was suitable for the sensitive and selective detection of glucose under the presence of glucose oxidase (GOx), which reduced O2 to H2O2. This analytical procedure for the detection of glucose had a linear range from 0.3 to 3 mM (R2 = 0.997), with a detection limit of 49 μM. The experimental results display the broad application prospects of the enzyme‐based MOFs in green and selective targets analyses.

Enzyme-Free Glucose Monitoring Patch

Monitoring of glucose levels in non-invasive biofluids, such as saliva and sweat, can advance personal health tracking. However, the approach remains challenging due to the low glucose concentration in saliva and sweat, about 100 times lower than in the blood. Commercial glucose sensors rely on glucose oxidase to measure blood glucose levels with enzyme reactions. The enzyme activity varies with pH, oxygen level, and temperature (more than 40ºC). Also, the method often suffers from cross-reactivity with other sugar molecules, such as maltose and xylose [1]. Thus, it is crucial to develop highly sensitive and stable non-enzymatic sensors for detecting glucose in non-invasive biological fluids.In this work, we present an enzyme-free, reagent-free electrochemical glucose monitoring patch based on a glucose imprinted polymer nanocomposite. The nanocomposite comprises redox-active chitosan-ferrocene (Cs-Fc) wrapped multi-walled carbon nanotubes (MWCNTs). The Cs-Fc is a polymer with covalently secured redox-active ferrocene, effectively preventing the out leakage of redox substances [2]. The incorporation of MWCNTs increases the surface area, conductivity, and electron transfer rate. The glucose imprinted layer was grown on the surface of the nanocomposite by electropolymerization of functional monomers o-phenylenediamine (o-PD) and 3-aminophenylboronic acid (APBA) in the presence of glucose templates. The successful removal of template molecules created glucose specific recognition sites in the polymer matrices. The sensor directly detected the presence of glucose upon their binding into these cavities. The electrochemical property of the modified sensor was characterized by cyclic voltammetry (CV) in a potential range of 0-0.5 V at a scan rate of 100 mVs-1 in 1x PBS (pH 7.4) solution. For glucose sensing, the sensor was immersed in a sample solution containing different glucose concentrations for 30 min. We have optimized the composition ratio and assay conditions for sensitive glucose detection. Preliminary results indicated a change in redox peak current of ~2.7 times relative to the control upon adding 1 mM glucose, as shown in Figure 1. The proposed glucose patch is label-free, reagentless, cost-effective, easy fabrication, and expected to be utilized for sensitive and selective glucose detection from sweat.

RuO2/rGO heterostructures as mimic peroxidases for colorimetric detection of glucose.

Thesuccessful synthesis of ruthenium oxide/reduced graphene oxide (RuO2/rGO) heterostructures by one-pot hydrothermal method using graphene oxides and RuCl3 as precursorsis reported. The heterostructures had high peroxidase-like (POD-like) activities, which catalyzes the oxidation of classical peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to create a blue colored reaction product. The catalytic activity was significantly enhanced by the synergistic effect between RuO2 nanoparticles and rGO. RuO2/rGO had a low Km of 0.068mM and a high vmax of 1.228 × 10-7 M·s-1 towards TMB in theTMB-H2O2 catalytic oxidation system. In addition, the POD-like activity originating from the electron transfer mechanism was confirmed by cytochrome C (Cyt C) oxidation experiment. A colorimetric method based on RuO2/rGO heterostructures was developed with good sensitivity and selectivity for glucose detection with a limit of detection of 3.34μM and a linear range of 0-1500μM. The RuO2/rGO heterostructures havepotential applications in the biomedical areas, such as biosensor and diagnostics.

Co3O4-chitosan/biomass-derived porous carbon molecularly imprinted polymer integrated electrode for selective detection of glucose

The detection of glucose (Glu) is of great significance in medical diagnosis, food processing and biotechnology. Rapid, accurate and convenient detection technology is particularly important. Herein, the Co3O4-PC nanocomposite grown on biomass-derived porous carbon (PC) was prepared by hydrothermal method and subsequent air calcination. Chitosan (CS) was electrodeposited on the surface of Co3O4-PC by potentiostatic deposition with Glu as the template molecule. Finally, the template molecule was eluted by cyclic voltammetry to create specific recognition sites for Glu, and a highly selective and stable Glu sensor was constructed. The obtained MIP (molecularly imprinted polymer)-Glu-CS/Co3O4/PC nanocomposites were characterized by scanning electron microscopy, Raman spectroscopy, cyclic voltammetry, chronoamperometry and so on. The results showed that the MIP-Glu-CS/Co3O4-PC had great catalytic performance for Glu detection with a linear range of 12.17 μM-2.3 mM, a detection limit of 4.01 μM, and a sensitivity of 407.5 μA cm−2 mM−1. The sensor has excellent selectivity and stability. This work provides a guide for improving the selectivity of nanozymes.

Highly Sensitive, Fast Response and Selective Glucose Detection Based on CuO/Nitrogen‐doped Carbon Non‐enzymatic Sensor

AbstractThis work presents development of an innovative CuO/nitrogen‐doped carbon composite (CuO−C) that may be effectively applied for the modification of a glassy carbon electrode (GCE) and creation of a non‐enzymatic sensor for glucose detection. The structure of the CuO−C nanostructured material was analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and atomic absorption spectroscopy. The prepared electroactive material, based on CuO including carbon structures derived from chitosan, showed excellent performance in terms of electrocatalytic oxidation of glucose. Under optimal conditions, the modified electrode displays high sensitivity (1546 μA mM−1 cm−2), a low detection limit (1.95 μM) and short response time (4 s).

Surface Functionalization of Enzyme-Coronated Gold Nanoparticles with an Erythrocyte Membrane for Highly Selective Glucose Assays.

Colorimetric glucose sensors using enzyme-coronated gold nanoparticles have been developed for high-throughput assays to monitor the blood glucose levels of diabetic patients. Although those sensors have shown sensitivity and wide linear detection ranges, they suffer from poor selectivity and stability in detecting blood glucose, which has limited their practical use. To address this limitation, herein, we functionalized glucose-oxidase-coronated gold nanoparticles with an erythrocyte membrane (EM-GOx-GNPs). Because the erythrocyte membrane (EM) selectively facilitates the permeation of glucose via glucose transporter-1 (GLUT1), the functionalization of GOx-GNPs with EM improved the stability, selectivity (3.3- to 15.8-fold higher), and limit of detection (LOD). Both membrane proteins, GLUT1 and aquaporin-1 (AQP1), on EM were shown to be key components for selective glucose detection by treatment with their inhibitors. Moreover, we demonstrated the stability of EM-GOx-GNPs in high-antioxidant-concentration conditions, under long-term storage (∼4 weeks) and a freeze-thaw cycle. Selectivity of the EM-GOx-GNPs against other saccharides was increased, which improved the LOD in phosphate-buffered saline and human serum. Our results indicated that the functionalization of colorimetric glucose sensors with EM is beneficial for improving selectivity and stability, which may make them candidates for use in a practical glucose sensor.

Advances in the Use of Graphene Nanocomposites for the Electrochemical Determination of Glucose: A Review

Background: Glucose detection is of great significance in biomedicine. In clinical medicine, diabetes seriously endangers human health. By accurately measuring the blood glucose content of diabetic patients, diabetes can be effectively monitored and treated. At present, there are many methods for measuring glucose content, such as chromatography, spectroscopy, and electrochemical methods. Among them, electrochemical glucose sensors are widely used because of their high reliability, low cost, and easy operation. Methods: Combining graphene with other nanomaterials (including graphene, metal oxides, semiconductor nanoparticles, polymers, dye molecules, ionic liquids and biomolecules) is an effective way to expand or enhance the sensing performance. Results: The composite of graphene and nanomaterials is an effective way to enhance the functionality of the electrochemical sensor. Graphene can accelerate electron transfer and realize direct electrochemistry and biological sensing. At the same time, graphene derivatives with rich composition and structure provide the possibility to further regulate their electrochemical performance. These graphene composite-based biosensors have shown excellent sensitivity and selectivity for glucose detection. Conclusion: Electrochemical glucose sensors based on graphene composite have received extensive attention. Although these materials have made significant progress in improving the sensitivity, lowering the detection limit and broadening the linear range, there are still facing challenges that require further study.

A novel contemporary molecular imprinting technique for non-enzymatic selective glucose detection

In this article we have reported highly selective detection of glucose using molecular imprinting technique (MIP), where unclad portion of a fiber is used as a substrate. The sensor works on non-enzymatic approach which makes it more promising. Employing unclad fiber with large core diameter not only eased the coupling but also provided enough evanescent field to interact with ambient medium. The presence of MIP in sensing region (unclad fiber) provides binding sites sensitive only to the size and shape specific target molecules that notably improved the selectivity. In addition, we have added carbon nano particles (CNPs) with high specific surface area to the polymer matrix, which provides numerous microcavities that worked as active sites. This enabled efficient penetration of analyte to the coated fiber surface. Herein, exponentially decaying evanescent field was elicited for establishing intensity modulated optical fiber sensors. Our experimental measurements showed that adding 0.0025 g CNPs to polymer matrix not only preserved the size of micro holes in MIP but also rendered high linear response in the clinical range of glucose concentration that is 2–10 mM. The present device introduced several advantages such as low-cost, online monitoring, fast response time (∼7 s), high stability and selectivity that makes it promising candidate for integrated sensors and biological medicine measurements.