Glucose Biosensor Research Articles

Computational Model-Assisted Development of a Nonenzymatic Fluorescent Glucose-Sensing Assay.

Deep-red fluorescence was implemented in this fully injectable, nonenzymatic glucose biosensor design to allow for better light penetration through the skin, particularly for darker skin tones. In this work, a novel method was developed to synthesize Cy5.5 labeled mannose conjugates (Cy5.5-mannobiose, Cy5.5-mannotriose, and Cy5.5-mannotetraose) to act as the fluorescent competing ligand in a competitive binding assay with the protein Concanavalin A acting as the recognition molecule. Using fluorescence anisotropy (FA) data, a computational model was developed to determine optimal concentration ratios of the assay components to allow for sensitive glucose measurements within the physiological range. The model was experimentally validated by measuring the glucose response via FA of the three Cy5.5-labeled mannose conjugates synthesized with Cy5.5-mannotetraose demonstrating the most sensitive response to glucose across the physiological range. The developed method may be broadly applied to a vast range of commercially available fluorescent dyes and opens up opportunities for glucose measurements using nonenzymatic assays.

The development of carbon nanostructured biosensors for glucose detection to enhance healthcare services: a review

In this review, the forefront of biosensor development has been marked by a profound exploration of carbon nanostructured materials for the specific application of glucose detection. Moreover, this progressive line of inquiry capitalizes on the distinctive attributes of carbon nanostructured materials such as carbon nanotubes, carbon quantum dots, and graphene which exhibit unique characteristics in the development of biosensor engineering design. It also enhanced analytical performances regarding the limit of detection, selectivity, sensitivity, and reproducibility towards glucose detection in biological samples. Most importantly, the strategic integration of carbon nanostructured-based biosensor architectures has played a significant role in advancements, characterized by heightened sensitivity, exquisite selectivity, and augmented stability in glucose detection processes. Furthermore, utilizing these advanced materials has engendered a transformative impact on electrochemical properties, propelling the biosensors to achieve rapid and precise glucose-sensing capabilities. The confluence of carbon nanostructures with biosensor technology has not only elevated the scientific understanding of glucose detection mechanisms. Still, it has also paved the way for miniaturized and portable biosensors. This transformative shift holds great promise for the realization of point-of-care diagnostics, representing a pivotal step towards durability and efficient glucose monitoring in health/medical care. These advancements emphasize the crucial role of carbon nanostructured-based biosensors in opening the way to a new avenue of superiority and effectiveness in diabetes management. Conclusively, the challenges and, in a forward-looking stance, the prospective futures of glucose biosensors anchored on carbon nanostructured frameworks were considered.

Development of flexible glucose biosensor for fish stress monitoring

Development of flexible glucose biosensor for fish stress monitoring

Development of fluorescence lifetime biosensors for ATP, cAMP, citrate, and glucose using the mTurquoise2-based platform

Development of fluorescence lifetime biosensors for ATP, cAMP, citrate, and glucose using the mTurquoise2-based platform

Advances in CuO Nanostructure-Based Glucose Biosensors: From Enzymes to Direct Oxidation

Advances in CuO Nanostructure-Based Glucose Biosensors: From Enzymes to Direct Oxidation

Fabrication and Potential Characterization of Silver‐Doped Zinc Oxide Glucose Biosensor

This work is devoted to studying and manufacturing a highly sensitive nonenzymatic glucose biosensing system of metal oxides via the sol–gel technique. The X‐ray diffraction patterns of all the prepared samples confirm that the samples present hexagonal crystal lattice structures of ZnO and Ag–ZnO nanoparticles. Ultraviolet (UV) analysis of all the samples is carried out to evaluate the absorption of silver in the UV region for electrical and chronoamperometric analysis. The transmittance of all the samples is observed, and the maximum transmittance is 11% for 4% AgZnO. Fourier transform infrared spectroscopy reveal the functional group stretching and vibration of the particles at different wavelength ranges. Scanning electron microsocpy analysis reveals the grain size and morphology of the samples, which decrease with increasing doping agent. Chronoamperometric analysis of all the samples reveals that the value increases with time for the 4% doped sample. The sensing response is also observed and is enhanced with increasing temperature for the 4% doped sample. The sensing response of the samples coated with carbon fiber electrodes is assessed from −0.2 to +0.5 V at a scan rate of 50 mV s−1.

Coral-like Ti3C2Tx/PANI Binary Nanocomposite Wearable Enzyme Electrochemical Biosensor for Continuous Monitoring of Human Sweat Glucose

With the continuous advancement of contemporary medical technology, an increasing number of individuals are inclined towards self-monitoring their physiological health information, specifically focusing on monitoring blood glucose levels. However, as an emerging flexible sensing technique, continuous and non-invasive monitoring of glucose in sweat offers a promising alternative to conventional invasive blood tests for measuring blood glucose levels, reducing the risk of infection associated with blood testing. In this study, we fabricated a flexible and wearable electrochemical enzyme sensor based on a two-dimensional Ti3C2Tx MXene nanosheets and coral-like polyaniline (PANI) binary nanocomposite (denoted as Ti3C2Tx/PANI) for continuous, non-invasive, real-time monitoring of sweat glucose. The exceptional conductivity of Ti3C2Tx MXene nanosheets, in conjunction with the mutual doping effect facilitated by coral-like PANI, significantly enhances electrical conductivity and specific surface areas of Ti3C2Tx/PANI. Consequently, the fabricated sensor exhibits remarkable sensitivity (25.16 μA·mM−1·cm−2), a low detection limit of glucose (26 μM), and an extensive detection range (0.05 mM ~ 1.0 mM) in sweat. Due to the dense coral-like structure of Ti3C2Tx/PANI binary nanocomposite, a larger effective area is obtained to offer more active sites for enzyme immobilization and enhancing enzymatic catalytic activity. Moreover, the sensor demonstrates exceptional mechanical performance, enabling a 60° bend in practical applications, thus satisfying the rigorous demands of human sweat detection applications. The results obtained from continuous 60 min in vitro monitoring of sweat glucose levels demonstrate a robust correlation with the data of blood glucose levels collected by a commercial glucose meter. Furthermore, the fabricated Ti3C2Tx/PANI/GOx sensor demonstrated agreement with HPLC findings regarding the actual concentration of added glucose. This study presents an efficient and practical approach for the development of a highly reliable MXene glucose biosensor, enabling stable and long-term monitoring of glucose levels in human sweat.

Cross-Disciplinary Glucose Biosensors: An ORMOSIL/Enzyme Material for Enhanced Detection

Cross-Disciplinary Glucose Biosensors: An ORMOSIL/Enzyme Material for Enhanced Detection

Conductive single enzyme nanocomposites prepared by in-situ growth of nanoscale polyaniline for high performance enzymatic bioelectrode

Enzyme-based electrochemical biosensors hold great promise for applications in health/disease monitoring, drug discovery, and environmental monitoring. However, inherently non-conductive nature of proteinaceous enzymes often hampers effective electron transfer at enzyme-electrode interface, limiting biosensor performance of enzyme bioelectrodes. To address this problem, we present an approach to synthesize polyaniline (PAN)-based conductive single enzyme nanocomposites of glucose oxidase (GOx) (denoted as PAN-GOx). To prevent multimerization of enzymes during nanocomposite synthesis and enable single enzyme wrapping, we activate GOx surface with phenylamine groups based on the programmed diffusion of reactants in the reaction solution. Subsequent in-situ polymerization enables the synthesis of nanoscale conductive PAN layer (∼2.7 nm thickness) grafted from individual GOx molecule. PAN-GOx retains 83% and 74% of its specific activity and catalytic efficiency, respectively, compared to free GOx, while demonstrating a ∼500% improved conductivity. Furthermore, PAN-GOx-based glucose biosensors show an approximately 16- and 3-fold higher sensitivity compared to biosensors prepared by using free GOx and a mixture of PAN and GOx, respectively. This study provides a facile method to fabricate conductive single enzyme nanocomposites with enhanced electron transfer, which can potentially be further modified and/or compounded with conductive materials for demonstrating high performance enzymatic bioelectrodes.

The importance of factorial design on the optimization of biosensor performance: immobilization of glucose oxidase as a case study.

Conventionally, the optimization of glucose biosensors is achieved by varying the concentrations of the individual reagents used to immobilize the enzyme. In this work, the effect and interaction between glucose oxidase enzyme (GOx), ferrocene methanol (Fc), and multi-walled carbon nanotubes (MWCNTs) at different concentrations were investigated by a design of experiments (DoE). For this analysis, a factorial design with three factors and two levels each was used with the software RStudio for statistical analysis. The data were obtained by electrochemical experiments on the immobilization of GOx-Fc/MWCNT at different concentrations. The results showed that the factorial DoE method was confirmed by the non-normality of the residuals and the outliers of the experiment. When examining the effects of the variables, analyzing the half-normal distribution and the effects and contrasts for GOx-Fc/MWCNT, the factors that showed the greatest influence on the electrochemical response were GOx, MWCNT, Fc, and MWCNT:Fc, and there is a high correlation between the factors GOx, MWCNT, Fc, and MWCNT:Fc, as shown by the analysis of homoscedasticity and multicollinearity. With these statistical analyses and experimental designs, it was possible to find the optimal conditions for different factors: 10mMmL-1 GOx, 2mgmL-1 Fc, and 15mgmL-1 MWCNT show a greater amperometric response in the glucose oxidation. This work contributes to advancing enzyme immobilization strategies for glucose biosensor applications. Systematic investigation of DoE leads to optimized immobilization for GOx, enables better performance as a glucose biosensor, and allows the prediction of some outcomes.

Development and Characterization of a Visual Eco-Friendly, Cost Effective Glucose Biosensor Using Immobilized Glucose Oxidase on Natural Fibers

Development and Characterization of a Visual Eco-Friendly, Cost Effective Glucose Biosensor Using Immobilized Glucose Oxidase on Natural Fibers

Enzyme free highly sensitive glucose biosensor based on Ag/Cu2O nanostructures deposited on TiO2 nanotube arrays

Enzyme free highly sensitive glucose biosensor based on Ag/Cu2O nanostructures deposited on TiO2 nanotube arrays

Electrochemical non-enzymatic glucose biosensors based on Au-thiol-linked molecular architectures

In this work, an electrochemical non-enzymatic glucose sensor consisting of di-methanethiol-grafted poly (3,4-propylenedioxythiophene), gold nanoparticles (Au NPs), and reduced graphene oxide (rGO) was synthesized by a one-step method through Au-S chemisorption. The structure and morphology of the as-prepared poly (ProDOT-(MeSH)2)/Au/rGO composite were characterized by FT-IR, XRD, EDX, TEM, SEM, and XPS, and the electrochemical performance of the composite was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on glassy carbon electrode (GCE). The results show that because of the hydrogen bond interaction between the thiol group on the polymer units and the functional groups on GO, poly (ProDOT-(MeSH)2)/Au/rGO was successfully prepared. In addition, due to the unique morphological structure of the composite and the ability to absorb glucose molecules through hydrogen bonds, the poly(ProDOT-(MeSH)2)/Au/rGO electrode possesses excellent selectivity and unique sensitivity (46.13 μA mM−1 cm−2) for sensing glucose in the linear range of 0.04–16.0 mM with a detection limit of (S/N = 3) 0.01. This paper demonstrates that the poly(ProDOT-(MeSH)2)/Au/rGO composite holds great promise for application as a new glucose sensor in life science.

Impact of microelectrode geometry and surface finish on enzymatic biosensor performance

Food production, environmental protection, biotechnology, and medicine, all depend on biosensors for measuring specific biological molecules. Among biosensors, enzymatic electrochemical biosensors have received particular attention due to their simple operation and enzymes’ inherent specificity. Researchers have extensively explored novel materials and biological designs to improve performance (i.e., sensitivity, linearity, limit of detection, and response time). However, in comparison, physical and geometrical design has not received the same attention. To this end, we compared platinum (Pt) microelectrodes with circular or fractal geometry with the same surface area (2D geometry). We also studied the effect of 3D geometry by nanostructuring both circular and fractal microelectrodes via electroplating Pt black. Fractal Pt black microelectrodes displayed the highest current density, charge storage capacity, and sensitivity towards H2O2. Next, we immobilized glucose oxidase onto various microelectrode geometries by microcontact stamping. Fractal Pt and Pt black glucose biosensors were 91.7% and 83.3% more sensitive than circular counterparts. Circular and fractal Pt black glucose biosensors were 63.0% and 55.9% more sensitive than Pt counterparts. Fractal geometry also provided better linearity and limit of detection. We modified enzyme layer thickness through multiple layer stamping and found a trade-off whereby increasing thickness increased sensitivity but also increased response time. Lastly, we developed a COMSOL Multiphysics numerical model to interpret the amperometric data and the impact of physical design on critical parameters. The work here will serve as a guideline for improving enzymatic electrochemical and other biosensors via physical design, which is simpler to modify than material or biological design.

Reusable gallium-based electrochemical sensor for efficient glucose detection

Among wearable sensing devices, electrochemical sensors are overwhelming in biochemical detection due to their simple design but high sensitivity. Most electrochemical sensors are disposable, which significantly impairs the service life. Here we present a reusable gallium (Ga)-based multi-layer electrochemical glucose biosensor to extend noninvasive monitoring of glucose in the interstitial fluid. This multilayer sensor includes Ga as a conductive interconnector, poly(3,4-ethylenedioxythiophene) as an electrode layer to prevent oxidation and metal leakage, a nano-Pt layer to enhance the electrochemical properties, and a nano-Prussian blue layer for reducing the hydrogen peroxide reduction potential. Most importantly, the biosensors can be renewed by automatically removing the modified nanocomposites via the electrolysis-induced bubbles and by electroplating without impairing the whole structure of the biosensor. The biosensor showed high sensitivity (24.6 μA mM-1 cm-2), wide linear range (0.01-26 mM), excellent stability (i.e., pH, long-term use) and superior selectivity, that is comparable to those of the current electrochemical tools for glucose detection. More importantly, incorporated with the reverse iontophoresis (RI), the Ga-based hybrid sensor was applied as a skin patch on mice for the in vivo noninvasive and continuous monitoring of ISF-borne glucose. The results showed a good correlation with that measured by blood glucometer. As a whole, this Ga-based electrochemical biosensor should endow new functions like biochemical analysis in biofluids for Ga-based soft bioelectronic sensing devices, in which almost are physical sensors. We believe that the reusability of electrochemically controllable processes may further inspire the development of more integrated and long-term stable gallium-based biosensing devices.

Study on the performance of MoS2/Au composites for non-enzymatic electrochemical glucose detection

Abstract Glucose concentration is considered an indicator for the diagnosis of diabetes, highlighting the importance of accurate glucose detection. Non-enzymatic electrochemical sensors have been extensively studied for glucose detection applications, with nanocomposites composed of molybdenum disulfide (MoS2) and gold nanoparticles (Au NPs) demonstrating high catalytic activity. In this study, a nanocomposite material composed of MoS2 and Au NPs (MoS2/Au) was synthesized and employed to construct a non-enzymatic electrochemical glucose biosensor. The detection limit of this sensor was explored, reaching as low as 1 mM. Additionally, compared to MoS2, the MoS2/Au nanocomposite exhibited a higher linear correlation coefficient and sensitivity, with a linear range of 1–25 mM and a sensitivity of 417.556 μA mM−1 cm−2. The sensor demonstrated excellent performance within the range of human blood glucose concentrations, showing potential for real-time monitoring and precise measurement of glucose levels. Furthermore, it exhibited good stability and reproducibility. These findings indicate the potential applications of MoS2/Au in biosensors and immunoassays.

Manganese Sulfanyl Porphyrazine-MWCNT Nanohybrid Electrode Material as a Catalyst for H2O2 and Glucose Biosensors.

The demetallation reaction of sulfanyl magnesium(II) porphyrazine with N-ethylphthalimide substituents, followed by remetallation with manganese(II) salts, yields the corresponding manganese(III) derivative (Pz3) with high efficiency. This novel manganese(III) sulfanyl porphyrazine was characterized by HPLC and analyzed using UV-Vis, MS, and FT-IR spectroscopy. Electrochemical experiments of Pz3 conducted in dichloromethane revealed electrochemical activity of the new complex due to both manganese and N-ethylphthalimide substituents redox transitions. Subsequently, Pz3 was deposited on multiwalled carbon nanotubes (MWCNTs), and this hybrid material was then applied to glassy carbon electrodes (GC). The resulting hybrid electroactive electrode material, combining manganese(III) porphyrazine with MWCNTs, showed a significant decrease in overpotential of H2O2 oxidation compared to bare GC or GC electrodes modified with only carbon nanotubes (GC/MWCNTs). This improvement, attributed to the electrocatalytic performance of Mn3+, enabled linear response and sensitive detection of H2O2 at neutral pH. Furthermore, a glucose oxidase (GOx)-containing biosensing platform was developed by modifying the prepared GC/MWCNT/Pz3 electrode for the electrochemical detection of glucose. The bioelectrode incorporating the newly designed Pz3 exhibited good activity in the presence of glucose, confirming effective electronic communication between the Pz3, GOx and MWCNT surface. The linear range for glucose detection was 0.2-3.7 mM.

Advancement in Glucose Biosensors and Current Development of Electrochemical Sensing

Advancement in Glucose Biosensors and Current Development of Electrochemical Sensing

A 3D printed dual screen-printed electrode separation device for twin electrochemical mini-cell establishment.

We describe a tiny 3D-printed polymethyl-methacrylate-based plastic sleeve that houses two disposable screen-printed electrodes (SPE) and enables each of the working electrodes (WEs) to work independently, on a different side of a thin barrier, in its own electrochemical (EC) mini-cell, while the SPE counter and reference units are shared for electroanalysis. Optical and EC performance tests proved that the plastic divider between WE1 and WE2 efficiently inhibited solution mixing between the mini-cells. The two neighboring, independently operating mini-cells enabled matched differential measurements in the same sample solution, a tactic designed for elimination of electrochemical interference in complex samples. In a proof-of-principle glucose biosensor trial, a glucose oxidase-modified WE2 and an unmodified WE1 delivered the EC data for the removal of anodic ascorbic acid (AA) interference simply by subtracting the WE1 (background) current from the analyte-specific WE2 current (from buffered sample solution supplemented with glucose/AA), at an anodic H2O2 detection potential of +1 V. The microfabricated SPE accessory is cheap and easy to make and use. For the many dual electrode SPE strips on the market for multiple analytical targets the new device widens the options for their exploitation in assays of biological and environmental samples with complex matrix compositions and significant risks of interference.

Effects of Sterilization on Cellobiose Dehydrogenase and Glucose Oxidase Based Glucose Biosensors

AbstractResearch on implantable glucose biosensors is driven by the need for innovative medical devices for continuous glucose monitoring in patients with diabetes mellitus. However, biosensor sterilization is a step that is widely omitted during the process of innovation. To compare the effects of gamma irradiation and chemical treatment with ethylene oxide (carbon microarray electrodes are fabricated, functionalized with glucose oxidizing enzymes (cellobiose dehydrogenase CDH or glucose oxidase GOx), and coated with a specifically designed zwitterionic polymer prior to the sterilization step. Cyclic voltammetry in the presence of 100 mm glucose of the biosensors before and after sterilization shows that gamma irradiation with a low radiation rate (25 kGy, 260 Gy h−1) does not induce a sensor performance loss, unlike the EtO treatment. In addition, no cytotoxic by‐products are released after gamma sterilization. Based on these results obtained with both glucose oxidizing enzymes (CDH and GOx), gamma irradiation of the glucose biosensors with a low dose rate is preferable to exposure to EtO for biosensor terminal sterilization.